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HP LaserJet 4L/4ML and 4P/4MP

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1. Clean the Transfer Roller using a dry lint free cloth DO NOT touch the Transfer Roller with your fingers If the problem persists replace the Transfer Roller Assembly 7 31 Troubleshooting Image Formation Troubleshooting Table 7 28 Background Scatter POSSIBLE CAUSE RECOMMENDED ACTION 1 Bad Media The moisture content con Try a different media see Paper ductivity or surface finish may not work Specifications in Chapter 2 correctly with the electrophotographic Drocess 2 Inside of printer is dirty toner may Clean inside of printer see Chapter 4 have leaked out of the toner cartridge Install a new toner cartridge if leaking 3 Printing on envelope seams Printing Move the text to an area without seams on an envelope seam can cause a back If not printing on seams try a higher print ground scatter problem density setting see item 6 below 4 Defective toner cartridge install a new toner cartridge 5 Dirty or worn Transfer Roller A worn Clean the Transfer Roller using a dry lint Transfer Roller can cause background free cloth DO NOT touch the Transfer due to improper bias voltages Roller with your fingers If the problem persists replace the Transfer Roller Assembly 6 Print Density set too low If the Print Adjust the print density to a higher Density is set too low then background setting through software through t
2. Table 7 13 Main Motor Error LaserJet LaserJet 4P AMP Ze AL AML LEDs Display Panel Description amp Recommendations See Table 7 2 57 ERROR The DC Controller has reported a general Paper Jam motor failure The Main Motor is controlled by the DC Controller PCA and seated into connector J601 Power cycle the printer If this doesn t clear the message 1 Reseat the Main Motor into the DC Controller connector 2 Inspect the Gear Train for debris that would block the free operation of the gears 3 The toner cartridge may not be rotating Refer to Drum Rotation Functional Check later in this chapter 4 Main Motor faulty Power up the printer and observe if stacker rollers rotate f not replace the Main Motor 5 Replace the DC Controller PCA 7 15 Display Panel Lo 61 67SERVICE 1 Power cycle the printer Ro 70 71 ERROR 2 Replace the Formatter PCA go 72 79 SERVICE OC Error light is oft the other lights display some pattern not oth erwise shown in this table Troubleshooting Printer Error Troubleshooting Table 7 16 NVRAM Error LaserJet 4ML LaserJet 4P 4MP d LEDs Display Panel Description amp Recommendations See Table 7 68 ERROR 68 ERROR indicates a recoverable error in 11 RAM Error 68 SERVICE NVRAM Press Continue to clear then check control panel settings One or more fields will have been reset to factory defaults during recov
3. 4 Foreign objects in beam path Any for eign objects will block the light from de veloping an image on the Photosensitive drum needs adjustment refer to the procedure under Beam to Drum Mirror Adjustment later in this chapter Remove the toner cartridge and check the laser beam printer slot for foreign objects Replace the toner cartridge if it is damaged Remove the Printer Cover and inspect the path from the Laser Scanner to the mirror looking for foreign objects in the beam path Replace the Laser Scanner Assembly if the lens is scratched Troubleshooting Image Formation Troubleshooting Table 7 22 X Vertical Black Lines POSSIBLE CAUSE RECOMMENDED ACTION 1 Toner cartridge is damaged Inspect the toner cartridge for a scratched photosensitive drum or toner leaking through worn seals Replace as necessary 2 Fusing Assembly is contaminated or Inspect the Fusing Assembly for toner damaged build up or scratches on the fuser rollers Try cleaning with alcohol Replace the Fusing Assembly if damaged 3 Static Eliminator Strip teeth are con Remove and inspect see Chapter 6 for taminated or defective removal procedure Clean using compressed air Replace if damaged Table 7 23 Horizontal Black Lines POSSIBLE CAUSE RECOMMENDED ACTION 1 Toner cartridge not seated properly Remove the cartridge and reinsert it 2 Toner cartridge defective Replace the cartridge 3 Repetitive defect I
4. 6 24 Removal and Replacement Internal Assemblies Power Switch Assembly LaserJet 4P 4MP only The Power Switch assembly is mounted on the right side of the printer chassis below the fan 1 Remove the Printer Cover 2 Remove the 3 self tapping screws Figure 6 23 callout 1 3 Remove the 2 machine screws Figure 6 23 callout 2 and pull the Power Switch Assembly outward to unplug from the DC Controller Note To access the second machine screw it may be necessary to re seat the power switch fully downward in its retaining slot if it was dislodged during cover removal Figure 6 23 Removing the Power Switch Assembly LaserJet 4P 4MP 6 25 Removal and Replacement Internal Assemblies Paper Guide Top Oblique Roller Assembly The assembly is held in place by one self tapping screw two plastic alignment tabs and a plastic latch tab Note It is not necessary to remove the Printer Cover although the front alignment tabs Figure 6 24 callout 2 are more easily accessible with the cover removed 1 Remove the 1 self tapping screw on the left side of the assembly Figure 6 24 callout 1 2 Lift the rear of the assembly while pushing down at the front and pull it to the rear slightly this releases the tabs Figure 6 24 callout 2 Figure 6 24 Removing the Paper Guide Roller Assembly To re install Ensure that the Guide Assembly is under the top door release button plunger and that t
5. 6 47 Feeder Guide Assembly and High Voltage SCT 6 49 Small Media Roller Assembly LaserJet 4P 4MP 6 50 Static Eliminator Strip Assembly 6 51 Toner Cartridge Lever Assembly 6 52 Top Door Switch Plunger Assembly 6 53 DC Controller Scanner Connector Assembly 6 54 PS1 Input Paper Sensor Arm 6 56 Contents Page 2 Chapter 6 Chapter Contents Troubleshooting Troubleshooting Flowchart 7 2 Paper Path and Components 7 4 DC Controller Diagram 7 5 Printer Error Troubleshooting 7 6 LaserJet 4L 4ML 7 6 LaserJet 4P 4MP 7 6 Priority of Errors 7 7 Recoverable Errors 7 7 Service Errors 7 11 LaserJet 4L 4ML 7 11 LaserJet 4P 4MP 7 11 Clearable Warnings LaserJet 4P 4MP 7 18 Image Formation Troubleshooting 7 19 Engine Test 7 36 Engine Test Button Location 7 36 Printing an Engine Test LaserJet 4L 4ML 7 36 Printing an Engine Test LaserJet 4P 4MP 7 37 Half Self Test Functional Check 7 39 Drum Rotation Functional Check 7 40 High Voltage Power Supply POE 7 41 Paper Curl 7 42 Adjustment Procedures 7 43 Leading Edge Adjustment 7 43 Beam to Drum Mirror Adjustment 7 44 Troubleshooting Tools 7 46 Repetitive Image Defect Ruler 7 46 Main Wiring Diagram 7 47 Chapter 7 Contents Page 1 Chapter Contents Parts and Diagrams How to Use the Part Lists and Diagrams 8 2 Ordering Parts 8 2 Orderin
6. LGE WH C2003A Made in U S A from foreign and domestic aiia XXXXXXXX SERIAL NO Figure 1 1 Sample Model and Serial Number Labels 1 3 Product information Specifications Specifications Table 1 1 Printer Dimensions LaserJet 4L 4ML LaserJet 4P 4MP C2003A C2015A C2005A C2040A i 36 cm 14 25 in 40 cm 15 75 in 37 cm 14 5 in 39 cm 15 5 in 16 5 cm 6 5 in 18 cm 7 in Table 1 2 Performance Specifications CATEGORY SPECIFICATION Print Speed Up to 4 pages per minute Monthly Usage Duty Cycle Up to 8000 pages Life Expectancy of toner cartridge Approximately 3000 pages Approximately 34 seconds Actual speed depends on data complexity and software handling efficiency Toner cartridge life can be extended by using EconoMode 1_A Product Information Specifications Table 1 4 Electrical Specifications WATTS WATTS typical VOLTS 4L AML 4P 4MP 120 Vac 10 50 60Hz 2 Hz 36 printing 180 printing 180 100 Vact 10 50 60Hz 2Hz standby 5 7 5 standby 10 220 Vac t 10 50 60 Hz 2 Hz 18 printing 180 printing 180 240Vac 10 50 60Hz 2Hz standby 5 7 5 standby 10 Operating current requirements Table 1 3 Environmental Specifications Operating Environment Temperature 10 C to 32 5 C 50 F to 90 5 F Humidity 20 80 no condensation Storage Environment Temperature 20 to 60 C 4 to 140 F no
7. 1 Maneuver the assembly back in place rotating some of the gears slightly to mesh if necessary 2 Tighten the screws beginning in the center and working outward Figure 6 16 CAUTION Do not tighten the upper two Main Motor screws until the Main Motor and Gear Train are both in place Tightening the screws without the Main Motor in place can damage the mount Figure 6 16 Screw Tightening Sequence Example LaserJet 4P shown 6 18 Removal and Replacement Left Side Assemblies Main Motor 1 Remove the Printer Cover and the Formatter Shield and PCA Figure 6 17 2 Remove the 1 machine screw through the access hole on the Gear Train Assembly approximately two 2 inches below the top of the Main Motor Figure 6 17 callout 1 3 Remove the 2 self tapping screws at the top of the Main Motor and pull the Main Motor straight up and out Figure 6 17 callout 2 Figure 6 17 Removing the Main Motor LaserJet 4L shown 6 19 Removal and Replacement Front Assemblies Front Assemblies Front Oblique Roller Assembly The Front Oblique Roller Assembly is located on the front of the printer and is accessible after removing the Paper Cassette It can be removed without removing the Printer Cover 1 Remove the Paper Cassette 2 Remove the 1 self tapping screw on the left of the Front Oblique Roller Assembly and tilt the assembly out at the bottom to remove Figure 6 18 callout 1
8. Combined Service Manual HP LaserJet 4L 4ML C2003A C2015A HP LaserJet 4P 4MP C2005A C2040A Copyright Hewlett ackard Company 1993 Jl Rights Reserved Repro uction adaptation or ranslation without prior ritten permission is pro ibited except as allowed nder the copyright laws ublication number 2005 90988 irst edition August 1993 econd edition March 1994 rinted in USA lewlett Packard Company 1311 Chinden Boulevard oise Idaho 83714 Warranty The information contained in this document is subject to change without notice Hewlett Packard makes no warranty of any kind with regard to this mate rial including but not limited to the implied warranties or merchant ability and fitness for a particular purpose Hewlett Packard shall not be liable for errors con tained herein or for inciden tal or consequential damaged in connection with the furnishing per formance or use of this ma terial WARNING Electrical Shock Hazard To avoid electrical shock use only supplied power cords and connect only to properly grounded 3 hole wall outlets Conventions This manual uses the following conventions Unless specifically stated otherwise information applies to all four printer models LaserJet 4L 4ML 4P 4MP Most procedures are com bined for all printers except where they differ substantially Color is used to emphasize items which are important to the material under d
9. Functional Overview Image Formation System Fusing Stage At the fusing station the toner is fused into the paper by heat and pressure to produce a permanent image The paper passes between a ceramic heating element protected by a thin Teflon sleeve and a soft pressure roller This melts the toner and presses it into the paper The ceramic heating element comes up to fusing temperature very quickly and thus does not require any power while the printer is on STANDBY These are the first Hewlett Packard LaserJet printers to employ this instant on fusing system Other laser printers use a halogen heating lamp and require frequent warming to maintain a minimum standby temperature This feature saves power while virtually eliminating the warm up period The fusing temperature is monitored by the DC Controller PCA using a thermistor TH901 The DC Controller maintains a temperature of about 180 C during print mode If the fusing system overheats about 215 C a relay opens the power circuit to the fusing heater causing a Fuser Error message If the fusing system exceeds 240 C the thermal fuse will open cutting off power to the fuser Ceramic Heating Element Paper Pressure Roller Figure 5 17 Fusing Film and Pressure Roller 5 39 Functional Overview Paper Feed System Paper Feed System The following topics are discussed in this section Paper Movement Overview Solenoids Photosensors Paper Out Sens
10. Lo 12 OPEN OR NO EP 1 Printer s Top Door is open and or the toner cartridge is missing or not installed Ra properly Reinstall toner cartridge and close g door H 2 Part of the Top Door that pushes the Error light is on plunger down is broken Replace the Top steady All Door 3 Top Door Switch Plunger Assembly is broken Replace see Figure 7 3 4 Toner Cartridge Lever Assembly is broken Replace the Assembly 5 Faulty Microswitch SW201 Top Door Switch on the DC Controller PCA Replace DC Controller PCA other lights are off Top Door Plunger Printer Chassis Top Rail eg Toner Cartridge Lever Sa Plunger Transfer Roller DC Controller PCA Sliding Brass Plate Switch Actuator Top Door Microswitch SW201 Metal Switch Arm Figure 7 3 Top Door Toner Cartridge Plunger and Lever Assembly 1 9 Troubleshooting Printer Error Troubleshooting Table 7 4 Memory Error LaserJet LaserJet 4P 4MP ALAML LEDs Display Panel Description amp Recommendations 20 MEM OVERFLOW 1 Too much data or data too complex 21 PRINT OVERRUN Turn Page Protection ON or to AUTO can be set within HP Explorer s Remote Control Panel 2 Add optional memory Error light is 3 Reduce the complexity of the print job blinking and all other lights LaserJet 4P AMP Press ISO are off resume printing Table 7 5 Manual Feed LaserJet LaserJet 4P 4MP GE AL 4ML
11. Resolution Enhancement REt The printer s Formatter PCA contains circuitry for Resolution Enhancement technology REt which modifies the standard video dot data on its way to the DC Controller to produce smoothed black to white boundaries REt is user adjustable from the front control panel LaserJet 4P 4MP only from HP Explorer s Remote Control Panel Print Quality Category or from some software applications Available settings are Light Medium Dark or Off The default setting is Medium Note REt settings sent from software or printer drivers override any control panel settings Print Density Adjustment Adjusting print density affects the line width boldness of the print image This is accomplished by varying the developer dc bias which controls the amount of toner applied to the photosensitive drum Print Density is adjustable through HP Explorers Remote Control Panel Print Quality Category The range of settings is from 1 lightest to 5 darkest The default setting is 3 5 17 EE ouv pauci acy eneen ee xi ell DLI UL CURA LI H using HP Explorers Remote Control Panel or through application software The default setting is Off Normal Mode Medium Density EconoMode Medium Density Figure 5 7 EconoMode vs Regular Print Note EconoMode does not affect print speed or memory usage 5 18 Functional Overview Formatter System Memory Management The printers use various methods to
12. TOP Main motor Scanner motor Primary voltage AC at Ap jl Primary voltage DC Developing bias ac TT Seege bm eg ees Developing bias DC ee 125 036 E m 0 71 en mg MN em EH EE RECHNEN TN ER EH Negative bias Print bias Between page bias CRS ER ER SEO RUD Im i E 2 Laser diode Note The transfer voltage changes according to the print sequence as follows Between page bias lower positive voltage than the print bias is applieo to the transfer charging roller to prevent the damage of the photosensitive drum 777774 Negative bias negative voltage is applied to the transfer charging roller for cleaning a Print bias positive voltage is applied to the transfer charging roller to transfer the toner on the photosensitive drum surface to the paper Figure 5 5 High Voltage Power Timing 5 11 Functional Overview Formatter System Formatter System The Formatter PCA is responsible for the following Receiving and processing ASCII data from the various printer interfaces Monitoring front panel input and relaying printer status information through the front panel and the bi directional I O Developing and coordinating data placement and timing with the print engine e Storing font information e Communicating with the host computer Video Timing l I
13. l Press the top door release button to open its top door 2 Remove toner cartridge from its box and cut it open Save the packing materials for possible cartridge storage 3 Shake the cartridge vigorously to distribute the toner evenly inside the cartridge see Figure 2 2 in Chapter 2 4 Grasp the toner sealing tape tab on the right side of the cartridge Pull firmly to remove the strip of sealing tape 5 Grasp the plastic cartridge body not the metal shutter linkage and slide the cartridge into the printer pushing it firmly into place Close the top door 3 9 Installation and Configuration Unpacking and Installation E Load the paper cassette L Pull out the paper cassette located at the lower front of printer and load approximately 100 sheets 4L 4ML or 250 sheets 4P 4A4MP of paper The rear of the stack should fit loosely under the two backstops at the rear of the paper cassette 2 Insert the front corner of the paper stack under the metal clip at the front of the cassette Note Failure to insert the paper under the metal clip will cause skewing or paper jams 3 Resting the paper cassette on a flat surface slide it into the printer F Attach the interface cable s 1 Open the I O Door on the printer s left rear side LaserJet 4L 4ML only Attach the I O cable securely to the printer Note Failure to attach the cable securely may result in an I O error 2 LaserJet 4L 4ML Align the cable
14. Figure 6 18 Removing the Oblique Roller Assembly 6 90 Removal and Replacement Front Assemblies Paper Cassette Assembly Field replaceable parts on the Universal Paper Cassette include the Tray Forms Size Guide s two compression springs Tray Forms Size Guide LaserJet 4L 4ML Note The forms size guides on the LaserJet 4P AMP are very easily removed and are not shown here 1 Remove the Paper Cassette from the printer and unload paper 2 Slide the guide all the way to the left and forward near the B5 adjustment line 3 Lift the inside corner up slightly while twisting the guide in a clockwise direction This frees the tab on the back side of the cassette allowing removal ie Figure 6 19 Removing the Tray Forms Size Guide LaserJet AL AML shown 6 21 Removal and Replacement Front Assemblies Compression Springs The Paper Cassette compression springs are located under the large pressure plate The LaserJet 4L 4ML is shown here Removal procedures for the LaserJet 4P 4MP are very similar 1 Remove the Paper Cassette from the printer and unload paper 2 Release the plastic latch on the lower left corner of the cassette assembly Figure 6 20 Rotate the metal bar up and out of the way Figure 6 20 Removing the Paper Cassette Assemblies 3 Release the large pressure plate from the catches on both sides LaserJet 4L 4ML only Raise the plate all the way up to access the compression
15. Image Formation Troubleshooting Table 7 26 Dropout POSSIBLE CAUSE RECOMMENDED ACTION 1 Single sheet of paper defective Try reprinting the job 2 Paper does not meet specs The pa Try a different paper lot see Media per moisture content conductivity or sur Specifications in Chapter 2 face finish may not work correctly with the printer s electrophotographic proc ess 3 High voltage power supply defective Replace the DC Controller low primary voltage 4 Transfer Roller defective Replace the Transfer Roller Table 7 27 Character Voids POSSIBLE CAUSE RECOMMENDED ACTION 1 Bad transparencies Transparencies Use Hewlett Packard approved can have this problem because they are jtransparencies refer to Media not designed for proper toner adhesion _ Specifications in Chapter 2 2 Printing on wrong side of paper The Check for the arrow on the paper label on the ream of paper indicates wrapper Be sure paper is loaded with the which side to print on The different sur arrow pointing down in the paper face properties of some papers may cassette problems if loaded wrong side up 3 Bad paper lot The surface of the pa Try a different paper lot see Media per may be too smooth or rough for Specifications in Chapter 2 proper toner adhesion 4 Bad Transfer Roller If the Transfer Roller has finger oils on its surface is dirty or is worn out this problem can re sult
16. Inspect and clean the contacts on the defective The High Voltage Connector High Voltage Connector Assembly Assembly mounts on the DC Controller Closely inspect the primary roller PCA and uses spring loaded pins to con contacts see Figure 7 2 lf damaged tact the toner cartridge replace the High Voltage Connector Assembly 4 High voltage power supply circuit is de Replace the DC Controller PCA fective not supplying the correct nega tive voltage 5 DC Controller PCA is defective If the Replace the DC Controller PCA DC Controller turns ON the laser beam continuously the entire surface of the Photosensitive drum is neutralized caus 7 Laser Scanner el fauly tum Replace the Laser Scanner Assembly ing laser on continuousl 8 Connector between the Laser Scanner Replace the Scanner DC Controller Assembly and DC Controller is defective connector 7 25 Troubleshooting Image Formation Troubleshooting Table 7 20 Faded Print POSSIBLE CAUSE RECOMMENDED ACTION 1 Toner supply low Shake the cartridge gently to redistribute the toner or replace the cartridge Change to a darker setting and retry printing 2 Print Density is set incorrectly Print Density is adjustable through software through HP Explorer s Remote Control Panel or through the front contro panel LaserJet 4P 4MP 3 EconoMode is on EconoMode saves Turn EconoMode off through soft
17. Laser Modulation e Development Formation of the Toner Image e Transfer Charge to transfer the image to paper The purpose of the Half Self Test Check is to determine which process is malfunctioning Perform the test as follows l Initiate a printer front panel self test 2 Open the printer s Top Door after the paper advances half way through the printer about ten seconds after the Main Motor begins rotation The leading edge of the paper should have advanced past the toner cartridge 3 Remove the toner cartridge 4 Open the toner cartridge s drum shield to view the drum s surface If a dark and distinct toner image is present on the drum s surface assume that the first three functions of the electrophotographic process are functioning conditioning writing and developing see Chapter 5 and troubleshoot the failure as a transfer problem If NO image is present on the photoconductive drum perform the checks shown on the following pages Troubleshooting Drum Rotation Functional Check Drum Rotation Functional Check The photoconductive drum located in the toner cartridge must rotate for the print process to work The photoconductive drum receives its drive from the Main Motor gear train To verify whether the drum is rotating 1 Open the printer s Top Door 2 Remove the toner cartridge 3 Mark the cartridge s drive gear with a felt tipped marker Note the position of the mark Install the toner
18. LaserJet 4L 4ML 6 6 Printer Cover LaserJet 4L 4ML 6 7 Printer Cover LaserJet 4P 4MP 6 9 Rear Door 6 12 A Control Panel LaserJet 4P 4MP 6 13 Left Side Assemblies 6 15 Formatter Shield and PCA 6 15 Gear Train Assembly 6 17 Main Motor 6 19 Front Assemblies 6 20 Front Oblique Roller Assembly 6 20 Paper Cassette Assembly 6 21 Tray Forms Size Guide LaserJet 4L 4ML 6 21 Compression Springs 6 22 Internal Assemblies 6 23 Laser Scanner ssembly 6 23 Fan 6 24 Power Switch Assembly LaserJet 4P 4MP only 6 25 Paper Guide Top Oblique Roller Assembly 6 26 Transfer Roller and Guide 6 27 Transfer Roller Bushings 6 28 Beam to Drum Mirror Assembly 6 29 continued on back Chapter 6 Contents Page 1 Rear Assemblies 6 30 Fusing Assembly 6 30 dd Assembly Components 6 31 Pressure Plate 6 31 Upper Fusing Assembly Teflon Sleeve and Heater Element 6 32 Pressure Roller 6 33 Delivery Assembly 6 33 Lower Delivery Roller 6 34 Lower Delivery Guide Exit Sensor Flag 6 35 Connector Assembly Fuser Entrance Guide 6 36 Upper Output Roller Assembly 6 37 Lower Output Rollers 6 38 Bottom Assemblies 6 39 DC Controller Assembly 6 39 Pickup Solenoid SL2 6 41 DC Controller Fuses 6 42 High Voltage Connector Assembly 6 42 DC Controller PCA 6 43 Pickup Feed D Roller 6 46 Pickup Assembly
19. Parr omer Pno sce aro ES LL Service Guide prizmas Less acca ermal Iess x x 2 HP PCL5 Printer Language Technical 5961 0601 Reference Information Package HP LaserJet Printer Family Paper 5002 1801 mE Specifications Guide HP LaserJet 4L Software Solutions Pkg C2003 60122 EIS HP LaserJet 4ML Windows Solutions Pkg C2015 60101 EE NE ions Pio ME E X gt lt KS ES ES ES x HP LaserJet 4ML Macintosh Solutions Pko C2015 60113 HP LaserJet 4P Software Pack C2005 60107 HP LaserJet 4MP Software Pack C2040 60101 1 Shipped with printer English version part number is shown Other translations are available see your local HP Sales Office 2 Includes DOS Windows and Macintosh solutions gt lt gt lt Print Utilities HP provides several utilities for enhancing use of the LaserJet printers in DOS MS Windows and Macintosh environments More information on specific utilities is included with each of the software packs listed in Table 1 5 Can FIP t U K 0800 96 02 71 Netherlands 06 0222420 Belgium Dutech 078 111906 Germany 0130 810061 Switzerland German 155 1527 Austria 0660 8128 For English service outside the above countries 31 20 681 5792 Product Information Technical Assistance HP AUDIO TIPS HP AUDIO TIPS available within HP ASAP is an interactive voice response system providing pre recorded answers to the questions most frequently asked by HP LaserJ
20. Sample self tests and printer reset information are also included Turn to this chapter for information on routine printer maintenance including consumables and printer cleaning procedures Paper jam procedures are also included Here you will find the basic theory of operation information required to understand the various printer systems and how they function together This chapter contains the step by step procedures for replacing all the printer s field replaceable units FRUs Assemblies are grouped by physical location in the printer Turn to Chapter 7 for diagnosing and troubleshooting printer problems Start with the general troubleshooting flowchart referencing the paper path and printer component location diagrams for assistance Error message tables and image defect samples are followed by engine test and other diagnostic procedures The chapter ends with more troubleshooting tools such as an image defect ruler and wiring diagram Use Chapter 8 to find any field replaceable unit FRU in the printers Exploded view drawings are accompanied by complete part number and description tables The parts index is a convenient tool for looking up any field replaceable unit FRU All parts are sorted both by part number and by part name Parts are cross referenced to their corresponding exploded view illustrations in Chapter 8 This appendix contains cabling and pin out information for the serial parallel and LocalTalk int
21. callouts 1 amp 2 3 LaserJet 4P 4MP Push the power switch grounding strap outward to provide clearance Figure 6 44 callout 3 4 Tilt the right edge opposite the Toner Cartridge Lever up first then lift carefully up and toward the right to remove CAUTION LaserJet 4P 4MP Carefully free the Small Media Roller drive shaft before lifting upward to avoid damage Figure 6 44 callout 4 Figure 6 44 Removing the Feeder Guide Assembly LaserJet 4P shown To re install LaserJet 4P 4MP Carefully align the Small Media Roller drive Shaft Figure 6 44 callout 4 before installing the Feeder Guide 6 49 Removal and Replacement Bottom Assemblies Small Media Roller Assembly LaserJet 4P 4MP 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 2 Turn the Feeder Guide black side up and remove the 1 screw from the Small Media Roller bracket Figure 6 45 callout 1 Remove the bracket and drive shaft with the attached gear CAUTION The drive shaft is lubricated Be careful not to Ss conttaminate the lubricant when handling 3 Using a small flat blade screwdriver push the 2 retaining tabs downward to release the Roller Assembly Figure 6 45 callout 2 Slide the assembly off the Feeder Guide
22. engine test microswitch theory 5 7 T technical assistance 1 20 1 22 test engine 3 25 timing diagram printer 5 41 5 42 toner cartridge 2 4 2 7 cleaning spills 4 7 control panel message 3 10 handling suggestions 2 6 installation 3 3 lever assembly 6 52 life expectancy 4 4 open cartridge storage 2 5 recycling 2 7 refilled 2 7 storage conditions 2 4 toner safety 1 14 tools required 6 3 Top Door Switch Plunger Assy 6 53 top door toner cartridge microswitch SW201 theory 5 6 Transfer Roller and Guide 6 27 Transfer Roller Bushings 6 28 transferring stage theory 5 31 transparency specifications 2 15 troubleshooting flowchart 7 2 troubleshooting tools 7 46 U unpacking and installation 3 2 3 8 Upper Output Roller Assembly 6 37 user installable assemblies 6 4 6 5 utilities print 1 19 V VCCI Statement Japan 1 16 W writing stage theory 5 27 SejON 3911S
23. textures moisture content drying processes composition etc Change the type of paper being used and re evaluate the paper curl results 7 AD Troubleshooting Adjustment Procedures Adjustment Procedures Leading Edge Adjustment The distance from the leading edge of a sheet of paper to the beginning of the printable area can be adjusted using VR301 located on the DC Controller PCA Leading edge is set at the factory for new units and only needs adjustment when the DC Controller is replaced VR301 can be accessed without removing any printer assemblies other than the paper cassette 1 Figure 7 7 Leading Edge Adjustment Run a printer engine test see Engine Test earlier in this chapter Measure the leading edge distance see Figure 7 7 Tf the distance is 1 5 to 2 5 mm no adjustment is necessary If adjustment is needed remove the paper cassette from the printer by sliding it all the way out Locate the access hole for VR301 see Figure 7 7 Turn VR301 clockwise to decrease the leading edge distance or counter clockwise to increase see Figure 7 7 Replace the paper cassette and run another test to compare Repeat 1 through 5 until the leading edge is within tolerance CCW CW increases decreases distance distance 7 43 Troubleshooting Adjustment Procedures Beam to Drum Mirror Adjustment The mounting for the Beam to Drum mirror has an adjustment on the right end to
24. the page If the printer invoked Image Adapt since the last time the self test was printed or the last power cycle that line will read Image Adapt Used Yes Note LaserJet 4L 4ML The Image Adapt information on the self test page resets every time the self test page prints or the printer is disconnected from its power source Page Protect A page s complexity rules eomplex graphics or dense text may exceed the printer s ability to create the page image fast enough to keep pace with the engine s printing process If a page is too complex it may print in parts for example the top half of data on one page and the bottom half on the next page Some print data loss is likely in these instances and the printer s Error light flashes Page Protect allows the Formatter to create the entire page image in memory before physically moving the paper through the printer This process ensures that the entire page will be printed Page Protect is user selectable through HP Explorer s Remote Control Panel Printer Memory Category The default setting is Auto E on Functional Overview Formatter System PJL Overview Printer Job Language PJL is an integral part of configuration in addition to the standard Printer Command Language PCL See PJL Software Commands in Chapter 3 for more information With standard Centronics cabling PJL allows the printer to perform functions such as Two way communication with th
25. when removing the DC Controller PCA from its mounting assembly 1 Remove the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 and the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 2 Remove the DC Controller Assembly Figure 6 36 Pickup Solenoid and High Voltage Connector Assembly Figure 6 37 3 Remove the 2 machine screws Figure 6 38 callout 1 Figure 6 38 Machine Screw Locations DC Controller PCA continued on next page 6 43 Removal and Replacement Bottom Assemblies 4 Remove the metal backing plate by releasing pressure on the curved portion then tilting the plate out Figure 6 39 CAUTION Be careful not to lose the metal grounding clip that is attached to the mounting plate Figure 6 40 callout 1 Figure 6 39 Removing the Metal Backing Plate continued on next page BAA Removal and Replacement Bottom Assemblies 5 Push the four plastic pressure tabs out to release Figure 6 40 callout 2 6 Squeeze the alignment pin together to release Figure 6 40 callout 3 7 Tilt the PCA outward at the top until it clears the lower two clips and remove the PCA Figure 6 40 callout 4 Figure 6 40 Removing the DC Controller PCA To re install After replacing the DC Controller PCA be sure to set the leading edge registration See Leading Edge Adjustment in Chapter 7 6 45 Removal and Replacement Bottom Assemblies Pi
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27. 2 on 4P 4MP Figure 6 27 callout 1 3 Remove the 2 self tapping screws Figure 6 27 callout 2 4 Slide the Fusing Assembly straight out from the rear of the unit some resistance may be encountered because of the two connectors to the DC Controller STALE AONO CONTACT OU wu Arer PRECA AT 0229204 t2 x Figure 6 27 Removing the Fusing Assembly LaserJet 4P shown 6 30 Removal and Replacement Rear Assemblies Fusing Assembly Components The following procedure describes the steps for disassembling the Fusing Assembly after it has been removed from the printer Please perform the steps in the sequence listed Pressure Plate CAUTION Do not remove or disturb the 2 stationary compression springs located at either end on top of the pressure plate Dislocation of these springs can cause poor fusing 1 Remove the spring from each end of the Pressure Plate Figure 6 28 callout 1 2 Open the Pressure Plate more than 90 degrees and lift it off its hinges Figure 6 28 Removing the Fusing Pressure Plate 6 31 Removal and Replacement Rear Assemblies Upper Fusing Assembly Teflon Sleeve and Heater Element 1 Unsnap and open the cable clip shown in Figure 6 29 callout 1 2 Remove the wires from the open cable clip and gently squeeze the connector to unplug 3 Unplug the second connector shown in Figure 6 29 callout 2 4 Squeeze the tab on the ceramic heater element connector
28. 26 scalabie Ho E L Typefaces Mamery Enhancement ST Na er oe E conoMode E de FAULTY REGISTRATION See Table 7 30 IHN PS IW Och SMEARED PRINT See Table 7 31 IMAGE SKEW See Table 7 32 Wess A GEZ Laser Jer vL amp o REA z soe e Univers Md Urien Mo it Vera dH RICH mp TOTMOURATION II Pr D HP Explorer pm seen COMPRESSED PHINT See Table 7 33 7 90290 Troubleshooting Image Formation Troubleshooting Table 7 18 Blank White Page POSSIBLE CAUSE RECOMMENDED ACTION OCCASIONAL BLANK PAGES 1 Software Configuration Make sure the application software is not sending incorrect page length requests or extra page eject commands 2 Network Configuration Some sharing Check with the Network Administrator devices on networks may generate a blank page as a separator 3 Multiple Feeds The printer may be Remove the paper from the paper feeding two or more pages at once be cassette and fan the edges of the paper cause the paper is difficult to separate to separate the pages Refer to Media Specifications in Chapter 2 to ensure paper meets recommendations 1 Sealing tape left in toner cartridge Remove ihe sealing tape 2 Empty or defective toner cartridge If unsure weigh the cartridge Full weight 852 grams 30 1 oz Empty weight 730 grams 25 8 oz Perform the Drum Rotation Functional Che
29. AML the front panel button to display the error go Only light code This code will be shown only while the button is pressed The following Oo c3 tables list possible error codes All four lights on without NOTE If no further error code is displayed pressing the yet all four lights remain on continuously front panel power cycle the printer If the condition persists replace the Formatter PCA Troubleshooting Printer Error Troubleshooting Table 7 7 Fuser Error LaserJet LaserJet 4P 4MP T AL 4ML LEDs Display Panel Description amp Recommendations DS 50 SERVICE 1 Remove power to the printer for 15 minutes If this doesn t clear the error Rc ga 2 Perform the Fuser Checks shown in the table below UE 3 Check the Fuses FU101 and FU201 on Ready and Er the DC Controller PCA Replace if faulty ror lights are on 3 Replace the DC Controller PCA and all others are off Table 7 8 Fuser Checks SUSPECT CHECK 1 Connector Contact Ensure that J103 and J204 connectors on the Fusing Assembly are seated securely into the DC Controller PCA connectors see Figure 6 29 in E 6 for locations Reseat the Fusing Remove the Fuser and measure the resistance between connectors J204 1 and J204 2 see Figure 6 29 in Chapter 6 for location Resistance should read approximately 440 K Ohms at 20 Deg C room temperature If the thermistor wire is open replace the Fusing Assembly Measu
30. Aallonpituus 777 795 nm Teho 5 mW Luokan 3B laser Product Information Safety Information Declaration of Conformity According to ISO IEC Guide 22 and EN 45014 Manufacturer s Name Hewlett Packard Company Manufacturer s Address 11311 Chinden Boulevard Boise Idaho 83714 1021 USA declares that the product Product Name s LaserJet 4L 4ML 4P 4MP Model Number s C2003A C2015A C2005A C2040A Product Options All conforms to the following Product Specifications Safety EN 60950 1988 A1 A2 IEC 825 1984 A1 1990 laser class 1 EMC CISPR 22 1985 EN 55022 1988 class BU EN 50082 1 1992 IEC 801 2 1991 prEN55024 2 1992 3kV CD 8 kV AD IEC 801 3 1984 prEN55024 3 1991 3V m IEC 801 4 1988 prEN55024 4 1992 1 kV Power lines Supplementary Information The product herewith complies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC D The product was tested in a typical configuration with Hewlett Packard Personal Computer and Test Systems Office of Quality Manager Boise Idaho USA June 15 1993 European Contact Your Local Hewlett Packard Sales and Service Office or Hewlett Packard GmbH Department ZQ Standards Europe Herrenberger Strae 130 D 7030 Bblingen FAX 49 7031 14 3143 1 13 Product Information Safety Information Toner Safety Note In case of toner spills skin and clothing are best cleaned by removing as much toner as possible with a d
31. Adjustment direction Laser scanner unit Adjusiment scale left up Beam to Drum Mirror right up Figure 7 8 Beam to Drum Mirror Adjustment TAS Troub leshooting Troubleshooting Tools Troubleshooting Tools Repetitive Image Defect Ruler First occurence of print defect Developing Cylinder 38 mm 1 5 in Primary Charging Roller 38 mm 1 5 in Face Down Delivery Upper Roller 38 mm 1 5 in Transfer Roller 44 mm 1 75 in Fusing Pressure Roller 47 mm 1 85 in Upper Fusing Assembly Film 75 mm 2 95 in Toner Cartridge Photosensitive Drum 75 mm 2 95 in Registration Roller 119 mm 4 7 in Figure 7 9 Repetitive Image Defect Ruler Troubleshooting Main Wiring Diagram iagram D ring 1 Main W ag NINH KC M3Snd ye euibu3 OEMS Sd sosuas IST Anong Adang Jo0MOg Od Ano Adang 1 J6MOg 2 oo I PSd Iosue odia BUIpUINA LOZMS m I a 90cf Od ZSd 10suas n AIST Moedeg 4 z l e d l isnipy I D mo zS Volete Aiddng samo l prousjog dnyoid P d LOSHA V r I e LO P L d 10suss ES CI IS Wl echt indui lt rmm x l H3lNiHd JO LNOH4 OL y uod AMY H TOH M e Figure 7 10 Main Wiring Diagram generalized 7 47 Troubleshooting Main Wiring Diagram 7 48 Parts and Diagrams Parts and Diagrams How to Use the Part Lists and
32. Fig 6 19 Tray Forms Size Guide 6 21 Fig 6 20 Paper Cassette Assemblies 6 22 Fig 6 21 Laser Scanner Assembly 6 23 Fig 6 22 Fan 6 24 Fig 6 23 Power Switch Assembly LaserJet 4P AMP 6 25 Fig 6 24 Paper Guide Roller Assembly 6 26 Fig 6 25 Transfer Roller 6 27 Fig 6 26 Beam to Drum Mirror 6 29 Fig 6 27 Fusing Assembly 6 30 Fig 6 28 Fusing Pressure Plate 6 31 Fig 6 29 Upper Fusing Assembly 6 32 Fig 6 30 Fuser Delivery Assembly 6 33 Fig 6 31 Lower Delivery Roller 6 34 Fig 6 32 Lower Delivery Guide and Exit Sensor Flag 6 35 Fig 6 33 Fuser Connector Assembly 6 36 Fig 6 34 Upper Output Roller Assembly 6 37 Fig 6 35 Lower Output Rollers 6 38 Fig 6 36 DC Controller Assembly 6 40 Fig 6 37 Pickup Feed Roller Solenoid 6 41 Fig 6 38 Machine Screw Locations DC Controller PCA 6 43 Fig 6 39 Metal Backing Plate 6 44 Fig 6 40 DC Controller PCA 6 45 Fig 6 41 D Roller 6 46 Fig 6 42 Pickup Feed Roller Assembly side view 6 47 Fig 6 43 Pickup Feed Roller Assembly bottom view 6 48 Fig 6 44 Feeder Guide Assembly 6 49 Fig 6 45 Small Media Roller Assembly 6 50 Fig 6 46 Static Eliminator Strip 6 51 Fig 6 47 Toner Cartridge Lever Assembly 6 52 Fig 6 48 Top Cover Switch Plunger Assembly 6 53 Fig 6 49 Releasing the Side Tabs 6 54 Fig 6 50 DC Controller Scanner Connector Location 6 55 Fig 6 51 Input Paper Sensor
33. LEDs Display Panel Description amp Recommendations MF FEED paper size 1 Insert paper into the manual feed slot ME FEEDJenv size This will fulfill he manual feed request 2 To avoid manual feed on this job press the front panel button to override the manual feed request and to feed paper from the paper cassette 3 To avoid manual feed on future jobs go into a software application or the HP LaserJet Explorer to change the setting from Manual Feed to Paper Cassette feed Data light is blinking and all other lights are off Troubleshooting Printer Error Troubleshooting Service Errors Service Errors inhibit further operation of the printer until some action is taken LaserJet 4L AML All lights will turn on in a steady state Pisis and holding the front panel button will reveal a pattern on the lights The error pattern will only be displayed as long as the front panel button is held down Use this pattern and the corresponding reference in Tables 7 6 through 7 15 to identify what type of service error has occurred LaserJet 4P AMP Service messages are displayed on the front Control Panel in the same manner as all other messages No action is required to display further error codes Table 7 6 Service Error LaserJet LaserJet 4P 4MP 4L 4ML LEDs Display Panel Description amp Recommendations Not Applicable There is a service error Press and hold ME ca LaserJet 4L
34. LIFE pgs es Cartridge 92274A 3000 When print becomes faint user replaceable shake cartridge to distribute remaining toner Transfer Roller RF5 0596 000CN 100 000 May affect print quality and or paper movement Pickup Feed D Roller RB1 3368 00CN 100 000 Look for glazing and or cracks Pickup Assembly RG5 0796 000CN 100 000 Look for glazing and or cracks gear wear sticky solenoids etc Front Oblique Roller RG5 0669 000CN 100 000 Look for glazing and or Assembly cracks Fusing Assembly 100 000 May affect print quality and 100 120 V 50 60 Hz RG5 0676 000CN or paper movement Look exchange part no C2003 69001 for marks on lower pressure roller or upper Teflon sleeve RG5 0677 000CN C2003 69002 The estimated toner cartridge life is based on Letter or A4 size paper with an average of 5 toner coverage and a medium density setting Toner cartridge life can be extended further by conserving toner using the printer s EconoMode feature 220 240 V 50 Hz 4 3 Maintenance Life Expectancy of Consumables Toner Cartridge Life The toner cartridge has been designed to simplify the replacement of the printer s major consumable parts The toner cartridge contains the printing mechanism and a supply of toner A toner cartridge will print approximately 3000 pages when using a typical word processing application in which text covers about 596 of the page see F
35. Paper Feed Solenoid SL1 Pickup Assembly LJ4L 4ML 8 elz Co Co 8 8 ER 1 CO A D 8 8 1 o U 8 1 U U U 8 7 8 8 1 8 0 0 UD U U N D 8 CO CO CO PLS L qe L o za 8 CO Pei A CO oco PO h 5 1 oller Fuser Pressure RB1 3100 000CN Roller Lower Output Assembl RG5 0682 000CN Roller Transfer Assembl RF5 0596 000CN co co C ind 1 8 5 J Dawvtc Tndav e Parts Index Alphabetical Parts Index Screw Mag JL XA9 0653000CN Ins Screw Scame XB474012090N Tas 8 12 Shaft Holder LJ4PAMP RBI 3365000CN 8 6 Shaft Top Door Hinge LJ 4L 4ML Shield High Voltage 1 RBI 2987000CN 8 6 Spring Compression 1 1 1 RS52232000CN 8 Spring Compression Large Spring Compression Small RS52229000CN 89 RS5 2254 000CN RS5 2255 000CN 8 12 C Jo CO LO CO Parts Index 7 Parts Index Alphabetical Parts Index 82 Spring Scanner Leaf RBI 3002000CN 8 6 CO CO co Co ID Io V Co S i Spring Top Door Latch LJ 4L 4ML RS5 2228 000CN Spring Top Door Latch LJ 4P 4MP RS5 2228 000CN Spring Torsion LJ 4L 4ML RB1 3138 000CN oring Torsion LJ 4P 4MP RB1 3138 000CN Static Eliminator Assembl RF5 0584 000CN 8 6 c Switch Acutua
36. Resetting the printer clears the printer s memory including unprinted data downloaded fonts and macros It also removes some error conditions and resets to factory default settings The printer can be reset at any time except when there is a service error condition LaserJet 4L 4ML 1 Hold the front panel button down for at least five seconds Release when all lights illuminate in succession from bottom to top 2 After the printer has finished the reset the Ready light comes on if there are no printer errors LaserJet 4P 4MP The LaserJet 4P 4MP has several kinds of resets as explained below Simple Reset A simple reset does the following 9 Clears the printer s page buffer 9 Removes all temporary typefaces and macros e Makes the current user selected defaults active making them the default values until you change them again e Purges the input buffer of the active I O the other I O buffer is not affected To perform a simple reset 1 Press to take the printer off line The On Line light goes off and ap GFFLIME appears on the display 2 While holding down the EMA key press LEER briefly 3 GF RESET appears on the display Then the printer returns to the on line pp READY state 3 96 Installation and Configuration Resetting the Printer The Menu of Resets Additional reset options are available through the Menu of Resets Use the Menu of Resets option with caution It can result in loss of
37. The Advanced Functions On Off configuration item is also user selectable The default setting On allows for Bi tronics two way parallel communications The Off mode disables the Bi tronics advanced functionality Functional Overview Formatter System Serial I O LaserJet 4P 4MP The LaserJet 4P 4MP printer supports RS 232 compatible serial communications The printer uses a 9 pin D subminiature connector See Appendix B for pin out information Pacing Serial Modes of Operation The Pacing configuration item is user selectable Available choices under Pacing are e DTR DSR default This mode primarily implemented for PCs has bi directional data flow which is paced using hardware pacing No XON or XOFF signals are sent e XON XOFF This mode is primarily intended for UNIX machines which cannot perform hardware pacing yet want bi directional data flow Data flow is paced using XON and XOFF signals to indicate when the printer is ready to accept new data from the host LocalTalk I O LaserJet 4ML 4MP The LaserJet 4ML 4MP printers implement the AppleTalk networking protocol through the LocalTalk hardware The LocalTalk network cable HP P N 92215N is connected through an 8 pin DIN connector on the printer s I O panel See Appendix B for more cabling information 5 15 Functional Overview Formatter System Control Panel LaserJet 4L 4ML j Status LED Lights The Formatter uses four lig
38. all cartons on the shipping pallet When shipping media across bodies of water wrap individual cartons as well Packaging must protect the media from physical damage Installation and Configuration Installation and Configuration Unpacking and Installation Unpacking and Installation Before unpacking the printer inspect the shipping container for signs of physical damage Since a damaged shipping box is an indication of improper handling during shipping the printer may also be damaged Note If the shipping container has any sign of damage unpack and power the printer ON with the carrier s agent present If the printer appears damaged or fails self test do not accept it A Choose the best location Verify that the printer location meets all EE listed in Chapter 2 B Unpack the printer 1 Remove the power cord the manuals and the toner package 2 Remove the printer from its box 3 Remove the outer packing material from the printer 4 Open the printer top door by pressing the door release button on the right side of the printer see Chapter 1 Figure 1 2 or 1 3 for location 5 Pull out the paper cassette 6 Remove the packing spacers from the inside of printer 2 on the Transfer Roller and from the paper cassette 2 cO BN RE n Ea ZEIL G tt Gi IKEA Note Interface cables are sold separately Refer to Chapter 8 for part numbers D Install the toner cartridge
39. and pull the connector free Figure 6 29 callout 3 5 Grip both ends of the Upper Fusing Assembly lifting it out Figure 6 29 Removing the Upper Fusing Assembly 6 32 Removal and Replacement Rear Assemblies Pressure Roller N OTE The plastic bushings under each end of the Pressure Roller can fall out of place and be easily lost 1 The Pressure Roller is now free Grasp both ends and lift it out Delivery Assembly 1 Pull out gently on the metal frame on either end of the Delivery Assembly to release the mounting pins Lift the assembly out Figure 6 30 de n Figure 6 30 Removing ihe Fuser Delivery Assembly To re install Ensure that the assembly is installed with its white plastic pressure rollers toward the back of the Fusing Assembly adjacent to the Lower Delivery Rollers It is possible to install the Delivery Assembly backwards 6 33 Removal and Replacement Rear Assemblies Lower Delivery Roller 1 Lift up on the bushing tab and slide the shaft inward and out of the bushing Figure 6 31 callout 1 2 Slide the bushing out from the metal frame and slide the Lower Delivery Roller out Figure 6 31 callout 2 Figure 6 31 Removing the Lower Delivery Soller 6 34 Removal and Replacement Rear Assemblies Lower Delivery Guide Exit Sensor Flag 1 Slide the Lower Delivery Guide slightly back to clear the center tab and lift the guide out being careful not to damage the Ex
40. and simultaneously On Line Form Feed Continue Enter E IN 1 J DD4F Menu C dl Reset EconoMode Installation and Configuration Using the Control Panel LaserJet 4P 4MP Control Panel Display and Lights The printer s control panel has a 16 character backlit LCD message display area and four LED status indicator lights A complete list of display panel messages is in Chapter 7 The following describes the functions of the four lights EconoModc Ready Light ON STEADY There are no error conditions detected The printer can only receive a print job when this light as well as the On Line light are on BLINKING The printer is receiving or processing data Do not take off line or switch power off until the light stops blinking OFF The printer is not ready to print SES the display panel for a message On Line Light ON STEADY The printer is ready to receive and process data BLINKING The printer is transitioning from the On Line to Off Line status OFF The printer is off line not ready to receive data Other control panel keys can now be accessed Form Feed Light ON STEADY There is unprinted data still in the print buffer Press Keita ETT to take the printer off line then press Paes to print the remaining data BLINKING Buffered data is being printed OFF No buffered data is in the printer EconoMode Light ON STEADY EconoMode is on Thi
41. buffered page data or printer configuration data You should only use it when You wish to restore the default printer settings e Communication between the printer and computer is interrupted You are using both the serial and the parallel I O ports and one of the ports is having problems To access the Menu of Resets 1 Press DENT to take the printer off line 2 Hold down both the EAA and ES keys for at least 10 seconds until RESET HEHU appears on the display 3 Use for Bl to cycle through the items 4 Press 21234 to select your choice of resets An asterisk appears by the reset option 5 Press CIENT to execute the reset The following table shows the three reset options Table 3 2 Menu of Resets LaserJet 4P 4MP Menu Selection Printer Response Explanation RESET MENU 09 MENU RESET RESET MENU restores most of the printer s factory default settings It also performs a simple reset Items in the Config Parallel and Serial Menus are not reset RESET MENU clears only the active input buffer RESET ACTIVE V O clears the input and output buffers for the active LC only and performs a simple reset RESET ALL WO clears the input and output buffers for both I Os and performs a simple reset RESET ACTIVE UO 09 RESET ACTIVE I O RESET ALL IO 09 RESET ALL I O 2 97 Installation and Configuration Resetting the Printer The Cold Reset LaserJet 4ML AP AMP Cold re
42. conserve and make the most of available memory Several of these are explained below Note LaserJet 4P 4MP If the printer encounters difficulty in managing available memory a Clearable Warning message will be displayed on the front control panel See Clearable Warnings in Chapter 7 for details Memory Enhancement technology MEt HP s Memory Enhancement technology MEt effectively doubles the printer s standard memory through a variety of font and data compression methods MEt also automatically compresses fonts for desktop publishing applications When printing graphics MEt analyzes each page as it is being printed and automatically applies a variety of methods to print the complete page at the correct resolution Two of these methods Image Adapt and Page Protect are user selectable through HP Explorers Remote Control Panel Printer Memory Category Note MEt is only available in PCL mode it is not functional when printing in PostScript mode 5 19 Functional Overview Formatter System Image Adapt LaserJet 4L 4ML Image Adapt uses a compression technique to allow printing of full page graphics using the printer s base memory The available settings are Auto On and Off The default setting is Auto Some data may be lost if Image Adapt is used To see if there has been some loss of graphic detail print a self test page and check the Image Adapt Used line in the Printer Information section of
43. copies refer to Ordering Related Documentation in Chapter 1 It is possible that print media can meet all of the general specifications listed and still not print satisfactorily because of the printing environment or other variables over which Hewlett Packard has no control Hewlett Packard neither warrants nor recommends the use of any particular media brand Properties are subject to change by manufacturers and HP has no control over such changes The operator should test particular media prior to large purchases All media should be stable at the 392 F 200 C temperatures encountered in the printer s fusing process CAUTION Use only media recommended for use in laser printers Printer damage resulting from use of incompatible media will not be covered by HP warranty or service agreements 2 8 87 x 7 5 in 98 x 191 mm DL 110 x 220 mm 4 3 x 8 6 in C5 162 x 229 mm 6 4 x 9 in Use the flat paper path only manual feed and rear output Operating Requirements Media Specifications Media Selection Guidelines To achieve the best possible print quality and avoid paper jams follow these guidelines for selecting paper 9 Use only high quality copier grade paper Avoid paper with embossed lettering perforations or texture that is too smooth or too rough e Colored paper should be of the same high quality as white photocopy paper The pigments must withstand the printer s fusing temperature of 392 F
44. correct for potential image skew problems The mirror is adjusted at the factory for new units but can lose its setting if the mirror is removed for any reason or if the adjustment screw has been loosened To adjust the Beam to Drum Mirror 1 Si Run a test print an Engine Test described earlier in this chapter or another self test print described in Chapter 3 Use a pencil or pen to draw a horizontal line across the top of each vertical line on the test print image see Figure 7 7 Place the edge of a tool with an exact 90 degree corner such as a drafting triangle along the leftmost vertical line of the test print image and draw a second horizontal line across the top of the page Measure the error between the lines drawn in step 2 and step 3 see Figure 7 8 If the distance is greater than 1 5 mm then adjustment is needed On the right end of the mirror assembly note the current adjustment setting if necessary make a mark on the printer body and or adjustment scale and loosen the adjustment screw Shift the mirror toward the front of the printer to move the image up on the right or toward the back of the printer to move the image up on the left Run another test print repeating the above steps until the image skew is within tolerance TAA Troubleshooting Adjustment Procedures Line drawn in Line drawn in About 1cm Step 2 Step 1 MM ER ENS Measure here Max 1 5mm
45. in refilled cartridges e Hewlett Packard has no control over the actual print quality of a refilled toner cartridge The print quality of HP LaserJet toner cartridges influences the customer s perception of the printer e Repairs resulting from the use of refilled toner cartridges are not covered under the HP warranty or maintenance contract Recycling Toner Cartridges In order to reduce the amount of plastics and other wastes entering our landfills Hewlett Packard has established a program for recycling used toner cartridges Parts that do not wear are re used in manufacture of new cartridges Plastic and other materials are recycled HP pays the shipping costs In addition a one dollar donation is shared by the Nature Conservancy and the National Wildlife Federation for each cartridge returned under this program To join this recycling effort follow the instructions included inside each toner cartridge box 2 7 Operating Requirements Media Specifications Media Specifications Several types of print media can be used with HP LaserJet printers provided the media specifications are met Using media that does not meet the specifications listed in this section may increase the incidence of paper jams cause premature printer wear and contribute to repair costs Note More detailed media specifications are available in the HP LaserJet Printer Family Paper Specification Guide part number 5002 1801 To order additional
46. pad WUE 1 DO SEET 16006 Ri CES i gah GUE TROAASDOL 165008SU Top L L1 saan AAREEIT DOE Zeep enees fea Seoul CEA dak ODE 1BOARAID GEES QUE Vy ten za XSftae AT eK OLE YRI 0068550 O83 fond HUE TROAKSDS 10008580TyPp uSk f tt a z AAEEETT E d bei aa UE RA SET 10002580l ybp ue az AAPEEIT UU fy cei anes FE EOOA EGUA 1 Oa fie 1 UE reg EH A pak UE RGARSDO 166008 UT ybb pfi ze AAEPELY C U0 desen in YS TS naBbOBEBUA OR ipa AT OU IHN T0000S SUT VPp afa Figure 3 7 LaserJet 4MP Service Mode Self Test Page 99 Installation and Configuration Printing a Self Test The LaserJet 4ML AP AMP Self Test Fields The numbered items below refer to the Service Mode PCL Configuration Self Test Page shown in Figure 3 7 Lm 9o Menu Selections Shows the current selections for all Service menu and user menus in the order that they appear in the control panel display refer to the Menu Maps Figures 3 4 and 3 5 Use this information to verify the various menu selections PS Menu Appears on the LaserJet 4P only if the Adobe PostScript SIMM 1s installed LocalTalk Information LaserJet 4MP only Lists the configured network name and node identification number EconoMode Status Shows current status ON or OFF Formatter Number Shows the Formatter PCA s serial number RAM Size Shows how much memory is installed in the printer 2048 Kbytes is standard If optional memory has been added a
47. springs To re install Before lowering the pressure plate back into place be sure that the larger compression spring on the left side will be seated properly on the underside of the plate 3 99 Removal and Replacement Internal Assemblies Internal Assemblies Laser Scanner Assembly 1 Remove the Printer Cover 2 Lift the foam cover and unplug the Fan connector Figure 6 21 callout 1 The Fan s power is via the Laser Scanner Assembly 3 Remove the 3 self tapping screws Figure 6 21 callout 2 Note The uppermost screw in Figure 6 21 callout 2 is under a protective light shutter Do not remove the scanner cover screw crossed circle in Figure 6 21 There are no field replaceable parts inside the Laser Scanner Assembly 4 Lift the Laser Scanner Assembly at both ends to remove there may be some connection resistance Figure 6 21 callout 3 ys WAGES ERT Bias e SE Removing the Laser Scanner Assembly Figure 6 21 6 23 Removal and Replacement Internal Assemblies Fan 1 Remove the Printer Cover 2 Lift the foam cover and unplug the Fan connector from the Laser Scanner Assembly Figure 6 21 callout 1 3 Pull down on both sides of the plastic bottom tab use a flat blade screwdriver on the LaserJet 4P AMP and tilt the bottom of the fan outward Figure 6 22 callout 1 4 With the bottom tab released pull upward on the top tab to remove Figure 6 22 callout 2
48. the door release button on the upper right side of the printer 2 Take out the toner cartridge Do not expose the toner cartridge to light for more than a few minutes Cover it while working on the printer 3 Pull out the paper cassette 4 If paper is in the paper feed area pull the paper to the right to release it from the oblique feed roller Then pull the paper straight out CAUTION _ Be careful not to get paper particles caught in the front oblique roller This can cause repeated jams Figure 4 3 Paper Feed Area Jam 5 If Step 4 clears the jam replace the paper cassette and the toner cartridge then close the top and rear doors The printer should return to the Ready state If it does not there may still be jammed paper in the printer Check the top and rear areas of the printer see the next page 4 9 Maintenance Clearing Paper Jams Paper Jams Inside The Printer 1 Remove the toner cartridge and paper cassette While holding the printer steady carefully pull the jammed paper straight out the front to remove it CAUTION Do not pull the paper straight up when removing it The toner on the paper may contaminate the printer and beam to drum mirror Figure 4 4 Clearing Jams from the Toner Cartridge Area 2 If the trailing edge of the paper is under the transparent cover pull the paper out and around to remove it Figure 4 5 Clearing Jams from the Paper Guide 4 10 Main
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50. 15 58 SERVICE Fan Error 7 16 60 67 SERVICE Formatter Error 7 16 70 71 ERROR Formatter Error 7 16 72 79 SERVICE Formatter Error 7 16 68 ERROR SVC NVRAM Error 7 12 A ac power distribution 5 8 accessories and supplies 8 5 8 26 adhesive label specifications 2 13 adjustment beam to drum mirror 7 44 leading edge 7 43 print skew 7 44 adjustment procedures 7 43 7 45 advanced functions I O theory 5 14 Appletalk 1 2 ASAP Automated Support Access Pro gram 1 20 assemblies bottom 6 39 6 56 front 6 20 6 22 internal 6 23 6 29 left side 6 15 19 rear 6 30 38 user installable 6 4 6 5 assembly Beam to Drum Mirror 6 29 DC Controller 6 39 DC Controller Scanner Connector 6 54 Feeder Guide 6 49 Form Guide 6 21 Fusing 6 30 Gear Train 6 17 High Voltage Connector 6 42 Laser Scanner 6 23 Paper Cassette 6 21 Paper Guide Top Oblique Roller 6 26 Pickup 6 47 Plunger Top Door Switch 6 53 Small Media Roller 6 50 Static Eliminator Strip 6 51 Toner Cartridge Lever 6 52 Upper Output Roller 6 37 Assist Line HP CSC 1 21 assistance technical 1 20 1 22 Audio Tips HP 1 21 B beam error 51 ERROR 7 13 Beam to Drum Mirror Assembly 6 29 Beam to drum Mirror adjustment 7 44 bi tronics parallel cable B 2 Bottom Assemblies 6 39 6 56 button front panel overview 3 9 button front panel usage 3 11 C capacities input tray 1 2 capacities output tray 1 2 cartridge slots 1 2 CDRH Center for Dev
51. 200 C for 0 1 second without deterioration Do not use paper with a colored coating that was added after the paper was produced 9 Pre printed forms must be printed with non flammable heat resistant inks that do not melt vaporize or release hazardous emissions when subject to the printer s approximately 392 F 200 C fusing temperature for 0 1 second o Always test a small sample of a new print media before purchasing large quantities 9 Give a copy of the table on the next page to your paper vendor to ensure that the paper you purchase meets the specifications for this printer More detailed specifications are in the HP LaserJet Printer Family Paper Specification Guide HP Part No 5002 1801 See Ordering Related Documentation in Chapter 1 non T IT 8 Jy WT Packaging Polylaminated moisture proof ream wrap Smoothness 100 to 250 Sheffield LaserJet 4P AMP only Heavier paper stock in the range of 36 to 42 pound 135 to 158 g m2 may be used but must use the flat paper path manual feed rear output and have a Sheffield smoothness rating not greater than 180 Note The flat paper path manual feed slot and rear face up delivery door is recommended for envelopes overhead transparencies and labels 2 11 Operating Requirements Media Specifications Envelope Specifications Choose envelopes that are well constructed They should lay flat and be sharply creased They should not be wri
52. 4 for clearing paper jams Error Amber STEADY The printer s top door is open or the toner cartridge is either missing or not installed correctly To correct the problem make sure the toner cartridge is installed completely and close the top cover until it snaps shut BLINKING The page is too complex Press the front panel button to continue printing There may be some data loss on the page Try setting Page Protect to On or Auto in the Printer Memory category of the HP Explorer Remote Control panel If the page still doesn t print correctly you may need to install the optional printer memory Installation and Configuration P eing tha Coitenl Barmi L ins Lenio cael The LaserJet 4L 4ML Front Panel Button Depending on what state the printer is in pressing the front panel button allows for control of printing tasks by either starting or resuming a printer function Table 3 1 explains front panel button usage Eens len 3 d Tuan Dana lfattarm Lierse rabie 2 Front Panel Bution Usage FUNCTION ACTION Lights RESULT Self Test Press button fortwo READY lighton Prints a Self Test page seconds briefly Continuous Hold down button All lights cycle Prints continuous self test while powering on through Release pages Press the button printer 4L about5 button when DATA to stop printing seconds 4ML about light only is on 15 seconds AML all lights on Press button for five Always available seconds or u
53. 6 Dust Cover Foam Rubber RB1 3392 000CN_ 8 6 Font Guide LJ 4P 4MP Foot Chassis RB1 3001 000CN_ 8 6 Formatter PCA LJ 4ML New CO E Formatter PCA LJ 4MP New C2041 67901 Formatter PCA LJ 4P Exchange C2006 69001 Formatter PCA LJ 4P New C2006 67901 Parts Index 3 Parts Index Alphabetical Parts Index 8 JE Co n5 8 co X X H 8 8 1 1 1 1 TI Ti CO ro ro TI CO n TI m Co PO Po 1 1 p co MO mn H CO CO CO Ip e CO BC 8 12 inge Font Cover LJ 4P 4MP RB1 3353 000CN O Cover Plate LJ 4MP onl C2040 40001 O Cover Plate LJ 4P C2005 40001 eyboard Overlay Chinese C2005 40017 8 1 Keyboard Overlay Danish C2005 40014 8 13 Grounding Plate LJ 4P 4MP RB1 3405 000CN CO D Qo CO N Co ho SL 2 8 I Co o w A ZN Parts Indesx 4 Parts Index Alphabetical Parts Index FIG DESCRIPTION PART NUMBER eyboard Overlay Dutch C2005 40009 8 Ae A H 1 4 4 j 1 1 d Nameplate LJ 4ML LJ 4L 4ML 82 8 K i AJA co j co Ee eyboard Overlay Norwegian C2005 40010 Ee CO E r IC IC 8 1 co rm Co co I Co j C1 C1 CO no O1 Parts Index 5 Parts Index Alphabetical Parts Index DESCRIPTION
54. 6 36 2 Remove the 1 machine screw holding the Pickup Solenoid from the lower side of the DC Controller Assembly the crossed circle shown in Figure 6 36 3 Unplug the Pickup Solenoid connector Figure 6 37 callout 1 and remove the solenoid Figure 6 37 callout 2 Note Becareful not to lose the small metal grounding tab that fits over the solenoid s mounting post E TRA ia X tactis cts ed Roller Solenoid on DC Controller PCA EEUU Figure 6 37 Pickup Fe To re install Be sure to align the placement tabs in their proper slots before tightening the screw 6 41 Removal and Replacement Bottom Assemblies DC Controller Fuses There are two in line fuses one on 220 V units on the component side of the DC Controller PCA shown in Figure 6 37 callout 3 The rated amperages are printed on the PCA Pull outward to remove High Voltage Connector Assembly This assembly is mounted on the component side of the DC Controller PCA and provides high voltage contact points to the toner cartridge shown in Figure 6 37 callout 4 To remove press the two tabs in on either side of the cover and lift 3t straight up and off 6 49 Removal and Replacement Bottom Assemblies DC Controller PCA If the DC Controller PCA is to be replaced the old PCA must first be removed from its mounting assembly CAUTION The DC Controller PCA is ESD sensitive Avoid using conductive tools such as metal screwdrivers
55. 7 Formatter PCA LJ 4P New FI Shield LJ 4ML FI Shield LJ 4ML Mini DIN ormatter PCA LJ 4ML New ormatter PCA LJ 4ML Exchange VO Cover Plate LJ 4MP Formatter PCA LJ 4MP New Formatter PCA LJ 4MP Exchange C2005 40018 Keyboard Overlay Taiwanese JI Z Co Oo co JOO Io PLP SO BERI CO D TT TI a e co GO cO co EN Universal Paper Cassette LJ 4L 4ML Universal Paper Cassette LJ 4P AMP Bushing D roller co co ine ce E Light Pipe LJ 4L 4ML Door I O LJ 4U 4ML oor Memory LJ 4L 4ML CO Bo CO CO n2 n2 Partoe Tndav 10 Parts Index Numerical Parts Index PART NUMBER DESCRIPTION FIG 8 12 Plate Fuser Ground LJ 4L 4ML 8 6 86 8 6 86 RB1 3003 000CN _ Spring Scanner Leaf 8 6 Pickup Feed D Roller LJ4L 4ML 8 11 RB1 3004 000CN 8 6 RB1 3073 000CN 8 5 RB1 3097 000CN 8 12 Roller Fuser Pressure 8 12 Roller Fuser Deliver 8 12 RB1 3107 000CN 8 12 8 12 Roller Fuser Conductive Rubber 8 12 RB1 3125 000CN 8 8 Front Panel Button LJ 4L 4ML 8 2 RB1 3129 000CN 82 CRG Pressure Piece LJ 4L 4ML 8 2 83 Shaft Top Door Hinge LJ 4L 4ML 82 Shaft Top Door Hinge LJ 4P 4MP 83 Button Lock LJ 4L 4ML 8 2 RB1 3133 000CN Juge Lock Button LJ 4L 4ML 82 8 2 RB1 3135 000CN _ Soring Right Torsion LJ 4L 4ML 8 2 RB1 3138 000CN Spring Torsion LJ 4L AML 82 8 3 RB1 3142 000CN Guide Forms Size 8 9 Parts Index 11 P
56. 7 23 Horizontal Black Lines 7 28 Tbl 7 24 Repetitive Defects 7 29 Tbl 7 25 Staining 7 30 Tbl 7 26 Dropout 7 31 Tbl 7 27 Character Voids 7 31 Tbl 7 28 Background Scatter 7 32 Tbl 7 29 Bottom Portion of Page Blank 7 32 Tb 7 30 Faulty Registration 7 33 Tbl 7 31 Smeared Print 7 34 Tbi 7 32 Image Skew 7 35 Tbl 7 33 Compressed Print 7 35 Tbi 7 34 High Voltage System Checks 7 41 Tb 7 35 Causes of Paper Curl 7 42 Tbl 8 1 Fasteners Used in the Printer 8 4 Tbi 8 2 Covers and Doors LaserJet 4L 4ML only 8 9 Tbl 8 3 Covers and Doors LaserJet 4P 4MP only 8 11 Tbl 8 4 Internal Components 1 8 13 Tbl 8 5 Internal Components 2 8 15 Tbl8 6 Internal Components 3 8 17 Tbi 8 7 DC Controller Assembly 8 19 Tbi 8 8 Gear Train Plate Assembly 8 20 Tbl 8 9 Paper Cassette LaserJet 4L 4ML 8 21 Tbi 8 10 Paper Cassette LaserJet 4P 4MP 8 22 Tb 8 11 Pickup Assembly 8 23 Tb 8 12 Fuser Assembly 8 25 Tb 8 13 Keyboard Overlays LaserJet 4P 4MP 8 26 Ai Am Chapter Contents Product Information Printer Features 1 2 Identification 1 3 Model and Serial Numbers 1 3 Specifications 1 4 Product Overview 1 6 External Assembly Locations LaserJet 4L 4ML 1 6 External Assembly Locations LaserJet 4P 4MP 1 7 Internal Assembly Locations 1 8 Safety Information 1 11 Laser Safety 1 11 Laser Sta
57. A o D A ww I D pi di label next to the front panel lights as shown in Attach the large label here Attach the small label here Figure 3 1 Attaching the Help Labels LaserJet 4L 4ML 3 6 Installation and Configuration PPamaslelem cn ES PPAR aT CSI A Ui Gori Cui REIR I Install Printer Drivers and Utilities optional Printer drivers are specialized programs designed to allow specific software applications to function with the HP LaserJet printers Printer utilities include such things as the HP Explorer program modules which enhance the usability of the printer and provide convenient access to printer features outside of specific software applications How to Obtain Printer Drivers First check the software s printer selection feature to see if the printer is listed among the available printers If it is not run the software s SETUP or INSTALL program to install a printer driver or printer file for the printer Here are some ways to obtain printer drivers and Software Application Notes for HP LaserJet printers e Check the Printing Software package to see if it includes a driver for your software Order an updated driver from the software vendor e Call Hewlett Packard at 303 353 7650 e Obtain a driver request form by fax through HP FIRST call 1 800 333 1917 e Download a driver through CompuServe s HP Forum To sign up for CompuServe call 1 800 848 8199 sate While waiting for a specific HP
58. Arm 6 56 Fig 7 1 Paper Path and Components 7 4 Fig 7 2 DC Controller PCA Components 7 5 Fig 7 83 Top Door Toner Cartridge Plunger Assembly 7 9 Fig 7 4 Engine Test Button and Printout LJet 4L 4ML 7 36 Fig 7 5 Defeating the Top Door Plunger LJet 4P AMP 7 37 Fig 7 6 Defeating the Exit Sensor Flag LaserJet 4P 4MP 7 38 Fig 7 7 Leading Edge Adjustment 7 43 Fig 7 8 Beam to Drum Mirror Adjustment 7 45 Fig 7 9 Repetitive Image Defect Ruler 7 46 Fig 7 10 Main Wiring Diagram 7 47 Fig8 1 Assembly Locations 8 7 Fig 8 2 Covers and Doors LaserJet 4L 4ML 8 8 Fig 8 8 Covers and Doors LaserJet 4P 4MP 8 10 Fig 8 4 Internal Components 1 8 12 Fig 8 5 Internal Components 2 8 14 Fig 8 6 Internal Components 3 8 16 Fig 8 7 DC Controller Assembly 8 18 Fig 8 8 Gear Train Plate Assembly 8 20 Fig 8 9 Paper Cassette LaserJet 4L 4ML 8 21 Fig 8 10 Paper Cassette LaserJet 4P 4MP 8 22 Fig 8 11 Pickup Assembly 8 23 Fig 8 12 Fuser Assembly 8 24 Fig 8 13 Keyboard Overlay LaserJet 4P 4MP 8 26 Fig B 1 Parallel Cable Pin Assignments B 2 Fig B 2 Serial Pin Outs DB 25 to DB 9 B 3 Fig B 3 Serial Pin Outs DB 9 to DB 9 B 3 Fig B 4 Connecting to END of a LocalTalk Network B 4 Fig B 5 Connecting to MIDDLE of a LocalTalk Network B 5 Tbl 1 1 Printer Dimensions 1 4 1 Tbl 1 2 Performance Specifications 1 4 Tbl 1 3 Environmental Sp
59. Cartridge Bracket 12 Fan FM1 5 Formatter PCA 13 Power Switch not shown 6 SIMM Slots 3 14 Beam to Drum Mirror 7 Main Motor 15 Laser Scanner Assembly 8 Gear Train Assembly Product Information Safety Information Safety Information Laser Safety The Center for Devices and Radiological Health CDRH of the U S Food and Drug Administration implemented regulations for laser products manufactured since August 1 1976 Compliance is mandatory for products marketed in the United States This printer is certified as a Class 1 laser product under the U S Department of Health and Human Services DHHS Radiation Performance Standard according to the Radiation Control for Health and Safety Act of 1968 Since radiation emitted inside this printer is completely confined within protective housings and external covers the laser beam cannot escape during any phase of normal user operation WARNING Never operate or service the printer with the protective cover removed from the Laser Scanner Assembly The reflected beam although invisible can damage your eyes Product Information Safety Information Laser Statement Finland The following applies to printer operation and servicing in Finland LASERTURVALLISUUS LUOKAN 1 LASERLAITE KLASS 1 LASER APPARAT HP LaserJet s AL 4ML 4P amp 4MP laserkirjoitin on k ytt j n kannalta turvallinen luokan 1 laserlaite Normaalissa k yt ss kirjoittimen suojakotelointi e
60. Diagrams How to Use the Part Lists and Diagrams The figures in this chapter illustrate the major subassemblies in the printer and their component parts A table material list follows each exploded assembly diagram Each table lists the reference designator item number for each part the associated part number for the item the quantity and a description of the part While looking for a part number pay careful attention to the voltage listed in the description column to ensure that the part number selected is for the correct model of printer Ordering Parts All standard part numbers listed are stocked and may be ordered from HP s Parts Direct Ordering or Parts Center Europe PCE Hewlett Packard Co Support Materials Organization 8050 Foothills Blvd Roseville CA 95678 Parts Direct Ordering 1 800 227 8164 U S Only Hewlett Packard Co Parts Center Europe Wolf Hirth Strasse 33 D 7030 Boeblingen Germany 49 7031 14 2253 Contact your local HP Parts Coordinator for other local phone numbers Parts and Diagrams How io Use the Part Lists and Diagrams Ordering Consumables Consumables and accessories such as those listed on page 8 5 and in Table 4 1 Chapter 4 may be ordered direct from Hewlett Packard The phone numbers are U S 1 800 538 8787 Canada 1 800 387 3154 Toronto 416 671 8383 United Kingdom 0734 441212 Germany 0130 3322 Contact your local HP Parts Coordinator for
61. Figure 6 45 Removing the Small Media Roller Assembly To re install Carefully align the Small Media Roller drive shaft Figure 6 44 callout 4 before sliding the Feeder Guide into place 6 50 Removal and Replacement Botiom Assemblies Static Eliminator Strip Assembly The Static Eliminator Strip is on the under side of the Feeder Guide Assembly WARNING The metal teeth on the Static Eliminator Strip are very sharp and can cause injury 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 2 Turn the Feeder Guide Assembly over and slide the Static Eliminator Strip to the right while pushing the center tab out to release Figure 6 46 callout 1 Figure 6 46 Removing ihe Static Eliminator Strip 6 51 Removal and Replacement Bottom Assemblies Toner Cartridge Lever Assembly The Toner Cartridge Lever Assembly is mounted on the surface of the Feeder Guide Assembly 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 2 Push upward on the plastic latch which holds the axis shaft in place Slide the axis shaf
62. Jet 4P 4MP Table 8 13 8 26 C2005 40002 C2005 40003 C2005 40004 C2005 40005 C2005 40006 C2005 40007 C2005 40008 C2005 40009 C2005 40010 C2005 4001 1 C2005 40012 C2005 40013 C2005 40014 C2005 40017 C2005 40018 Keyboard Overlays LaserJet 4P 4MP Keyboard Overlay Euro English Turkish Portuguese German Spanish French Italian Dutch Norwegian Polish Swedish Finnish Danish Chinese Taiwanese Appendix A Parts Index Parts Index Alphabetical Parts Index Alphabetical Parts Index 85 8 8 a E 8 DD 8 8 CD 3 UJ O a 8 1 O CH m 8 CO Co co ao Q CO n2 Q CO co C z Cover Main LJ 4P 4MP CRG Pressure Piece LJ 4L 4ML CRG Pressure Piece LJ 4P AMP co E CO DN CH CO N J co I DC Controller PCA 100 120V LJ 4P 4MP Exchange C2005 69003 DC Controller PCA 100 120V LJ 4P 4MP New RG5 0822 000CN Parte Inrlov 9 Parts Index Alphabetical Parts Index DESCRIPTION PART NUMBER DC Controller PCA 220 240V LJ 4L 4ML Exchange C2003 69004 DC Controller PCA 220 240V LJ 4L 4ML New RG5 0767 000CN DC Controller PCA 220 240V LJ 4P A4MP Exchange C2005 69004 DC Controller PCA 220 240V LJ 4P 4MP New RG5 0823 000CN ela 8 8 8 8 8 CO CO no PO oC Po co co CO ho h5 8 Drive Gear LJ4PAMP 1 RS50364000CN 8
63. LaserJet printer B driver you can substitute a similar printer driver such as a driver for the HP LaserJet IIT IIIP or 4 printer These substitute drivers will allow you to use the printer but they do not support all of the printer s features 23 7 Installation and Configuration Unpacking and installation Using the Printing Software Package The Printing Software package supplied with the printer provides many useful programs and utilities including o Printer drivers for several popular software applications e Utilities for automatically copying printer drivers onto your hard disk o Software Application Notes for the above applications The HP Explorer utilities including e A setup program which installs other HP Explorer modules and automatically updates the computer s AUTOEXEC BAT and CONFIG SYS files Use the setup program to add or delete any of HP Explorer s utilities at any time e The HP Explorer Remote Control Panel allows changes to printer settings from the computer s screen It supplements the software s printer support to permit complete control over the printer s features e The HP Explorer Status Monitor is a Terminate and Stay Resident TSR program that automatically displays messages from the printer on the computer s screen whenever the printer s status changes e The HP Explorer Travel Guide is a guide to the printer s features It also serves as an on line help utility w
64. MP 7 37 Troubleshooting Engine Test 5 On the rear of the Fusing Assembly use a pencil or flat blade screwdriver to press the flag mechanism for the Exit Paper Sensor PS3 in just until it is about flush with the face of the fuser see Figure 7 6 Note Do not push the PS3 flag in more than about 1 8 inch 8 mm If PS3 is pressed in too far the printer will register a power on jam and the Engine Test will not print If this occurs decrease the depth of the PS3 flag power cycle the printer then retry the Engine Test Press flag in flush with face of fuser Figure 7 6 Defeating the Exit Sensor Flag LaserJet 4P 4MP 6 Plug the ac power cord into the printer 7 Exert downward pressure on the the toner cartridge through the light blocking paper while pressing the Engine Test button SW301 Use a pencil or other non metallic object to reach through the access hole in the Gear Train plate similar to that shown in Figure 7 4 8 If the single page Engine Test does not print power off the printer check the Top Door Plunger to be sure it is held all the way down step 4 and adjust the depth of the Exit Paper Sensor flag as described in step 5 7 38 Troubleshooting Half Self Test Functional Check Half Self Test Functional Check The electrophotographic process can be subdivided into the following stages Cleaning Physical and Electrostatic e Conditioning Primary Charge Roller e Writing
65. Non Volatile Memory If it is necessary to replace the Formatter PCA the page count should be reset to the printer s original page count to reflect the age of the print engine Use the following procedure to set the page count Before removing the old Formatter PCA print a front panel self test to verify the current page count of the printer if possible Mote If it is not possible to print a self test try to verify the page count before replacing the Formatter PCA by following steps 3 through 5 below After verifying the page count from the old Formatter PCA replace it with the new PCA as described in Chapter 6 1 Enter the Service Mode as described in this section 2 When CE MODE is displayed press the ETE key to access the Services Meat 3 Press the ES key to step through the menu S XXXXXX is displayed XXXXXX represents the page Count E stored in the printer s Non Volatile Memory The underlined character denotes the cursor position 4 Press the KSC digit key to scroll the cursor to underline the desired 5 Press the BB key to select the correct value 6 Press BOS to store the new value in NVRAM to return the 7 Set each ded in the same manner Press PARENS display to 5 id a second time to exit Service Mode Installation and Configuration Service Mode LaserJet 4ML AP ANIP Setting the Cold Reset Default LaserJet 4P 4MP The default paper size for Formatter PCAs in Europ
66. Print temperature contiol E r page tem mmm p E 1210 1 6 121016 BEES in i EES IB iC C BA AB C 1140 e 036 1 69 2 125 1 20 Positive bias Between page bias Functional Overview Functional Overview Basic Printer Functions Basic Printer Functions This section of the manual presents a generalized functional overview of the printer It is designed to provide an understanding of the processes that occur during printing The following basic printer functions are discussed e DC Controller System e Formatter System e Image Formation System e Paper Feed System e Power System e Basic Sequence of Operation Figure 5 1 is a generalized block diagram of the printer uu FUE acri He BEE ANE caer ORS a m To external device 1 eg host computer via the bi directional UO uz ce er 4 IFont Ct L 1 t Formatter PCA Scanning mirror JL Ve een t i 1 Laser BD dioda circuit i i I i oa 1 H 1 1 t D i Le ce Ee t c wee we ee EE EE KEE d unit Q Q Q o z gt 3 Y O gt Face up dalivery slot SYSTEM 6 e A m m a mmm mom m eee en ee M m a a M e m e e am wm mom m wn m a UP om EOE wm Am o m er a mo e rr oo ooo m ooo o Figure 5 1 Printer Functional Block Diagram 5 2 Functional Overview DC Controller Power System DC Co
67. RIPTION REF Rz5 2010 000CN 1 Universal Paper Cassette RB1 3338 000CN 9 nsz2254000CN 1 Spring Compression 10 mBBi 3339 0000N 1 Lever 12 RB1 3341 000CN 1 ty Legal 8 99 Parts and Diagrams Accessories and Supplies Figure 8 11 Pickup Assembly Table 8 11 Pickup Assembly a ee PART NO DESCRIPTION 1 Pickup Assembly RG5 0668 000CN LaserJet 4L 4ML RG5 0796 000CN LaserJet 4P 4MP 4 1 Pickup Feed D Roller RB1 3029 000CN LaserJet 4L 4ML HB1 3368 000CN LaserJet 4P 4MP 8 23 Figure 8 12 Fuser Assembly 8 24 Parts and Diagrams Accessories and Supplies Table8 12 Fuser Assembly REF PARTNO DESCRIPTION 1 Fuser Assembly 100 120V RG5 0676 000CN New C2003 69001 Exchange 1 Fuser Assembly 220 240V RG5 0677 000CN New C2003 69002 Exchange RB1 2981 000CN ab Fuser Release Og RG5 0690 000CN Guide Fuser Entrance RB1 3097 000CN Flag Exit Sensor RB1 3100 000CN Roller Fuser Pressure RB1 3103 000CN Roller Fuser Deliver RB1 3109 000CN Roller Fuser Conductive Rubber 20 1 Fuser Film Assembly RG5 0678 000CN 100 120V RG5 0679 000CN 220 240V RS5 2224 000CN 2 Spring Fuser Hook XB2 8300 809CN Screw wistar washer M3X8 RG5 0681 000CN Fuser Delivery Assembl RB1 3107 000CN Roller Deliver RB1 3108 000CN Spring Deliver 8 25 Parts and Diagrams Accessories and Supplies Figure 8 13 Keyboard Overlay Laser
68. RST Fax Information Retrieval Support Technology 1 20 I LO Door 6 6 identification printer 1 3 Image Adapt theory 5 20 image formation theory 5 22 5 32 troubleshooting 7 19 7 35 image skew adjustment 7 44 indicatorlights 3 10 Input Paper Sensor PS1 theory 5 36 Input Paper Sensor Arm 6 56 inputtrays 1 2 intelligent on off theory 5 10 installation and configuration 3 1 3 30 help labels 3 6 power cord 3 5 printer 3 2 3 8 printer drivers 3 7 toner cartridge 3 3 interface cables attaching 3 4 B 4 B 6 internal assemblies 6 23 6 29 internal assembly locations 1 8 J Japanese VCCI Statement 1 16 L laser and scanner drive theory 5 5 laser statement Finland 1 12 Laser Scanner Assembly 6 23 leading edge adjustment 7 43 LEDs 3 10 left side assemblies 6 15 6 29 life expectancy of consumables 4 3 4 5 lights room flickering effect 2 2 lights LEDs functions 3 10 loading the paper cassette 3 4 LocalTalk feature 1 2 LocalTalk cabling information B 4 B 6 LocalTalk I O theory 5 15 Lower Output Rollers 6 38 M Main Motor 6 16 main motor error 67 ERROR 7 15 main motor theory 5 7 main wiring diagram 7 47 7 48 maintenance 4 1 4 12 Manual Feed mode control panel message 3 10 manual feed printing theory 5 38 Material Safety Data Sheet MSDS 1 14 matrix printer features 1 2 media selection guidelines 2 10 media specifications 2 8 2 16 memory configuration 3 21 Memor
69. abel Specifications Use the following guidelines when selecting labels e The top sheet printing surface must be of copier quality and provide good toner adhesion The carrier sheet backing sheet must be compatible with the temperatures and pressure of the fusing process and must be coated for easy release of the top sheet The adhesive must be stable at the 392 F 200 C temperatures encountered for 0 1 second in the printer s fusing process and must not produce emissions that exceed exposure levels or threshold limits established by OSHA and other safety agencies Adhesives must not come into direct contact with any part of the printer Labels must be arranged on the carrier sheet so that any exposed spaces run lengthwise down the sheet Using label stock with spaces between the horizontal rows of labels can often result in labels peeling off during printing causing serious jamming and possible printer damage A wide selection of suitable labels is available through Hewlett Packard A list of available sizes is in the HP LaserJet Printer Family Paper Specification Guide HP Part No 5002 1801 See Chapter 1 for ordering information or contact your local authorized HP dealer CAUTION Do not attempt to print on label sheets after any of the labels have been removed from the sheet Damage to the printer may result 9 13 Operating Requirements Media Specifications F A ellneeizam aaa Draam ER Let fable 2 6 Ache
70. ached this position in the paper path The Registration Position B signals the DC Controller to monitor if the scanner motor is up to speed and the fuser is at the correct temperature When both conditions are met the paper continues to the Top Position If these conditions have not been met solenoid SL1 is engaged to stop the registration roller until the printer is ready When the printer is ready SL1 disengages and paper proceeds to the Top Position The Top Position C When paper passes through the Top Position the DC Controller sends a signal to synchronize the image on the photosensitive drum with the top of the page 5 36 Functional Overview Paper Feed System Printing from the Paper Cassette Paper motion begins when the DC Controller PCA after receiving a PRINT signal starts the Scanner Motor the Main Motor and the fusing heaters The Pickup Solenoid SL2 is energized for 0 5 seconds the pickup roller and the registration roller rotate and feed a sheet of paper from the Paper Cassette to the Registration Position where the registration roller is stopped by solenoid SL1 if necessary until the Scanner and Fuser are ready While the registration roller is rotating the oblique rollers are aligning the paper s left edge correctly to prevent skewing see Figure 5 19 Left side of the main unit Oblique roller Figure 5 19 Oblique Roller Paper Alignment The Formatter PCA sends the VDO signal to
71. ack Assembl Spring Torsion RS5 2228 000CN Spring Top Door Latch Door Memor Spring Too Door Compression Screw Top Door Door Top Nameplate LaserJet 4L Nameplate LaserJet 4ML Cover assembly does not include items 1 2 and 12 8 9 Parts and Diagrams Accessories and Supplies Covers and Doors LaserJet 4P AMP only Figure 8 3 8 10 Parts and Diagrams Accessories and Supplies Table 8 3 Covers and Doors LaserJet 4P AMP only PART NO QTY DESCRIPTION RE RG5 0810 000CN 1 CoverAssembly Hinge Font Cover Shaft Top Door Hinge Guide Lock Button 6 BBi 379 000CN 1 Spring Left Torsion Spring Right Torsion 8 RF50681 000CN 1 Cover Main 9 RBI31300000N 2 CRG Pressure Piece 108 RBBi 313 amp 000CN 1 Spring Torsion 11 RS5222 00CN 1 Spring Top Door Latch Plate Grounding Spring Top Door Compression 14 XA 0634 000CN 2 Screw TopDor RFI Shield Control Panel PCA 16D Co040 00001 1 Nameplate LaserJet4MP i6F see Table g 13 17 BS52255000CN 1 Spring Font Door Torsion 18 RGzo812000CN 1 SIMMCoverAssemby 19 RG5 0815 000CN 1 Display Cabe 99 7 17 18 19 20 20 V06 Keyboard Overlay Localized C2005 4000 I O Cover Plate LaserJet 4P 20 Co040 4000 UD Cover Plate LaserJet 4MP vos XD2 100 242CN E Clip 8 11 Pa
72. aia a P1 l bi Pun s i mLrino Qi Prio e Fs te aA D iirit gpen b ing 5 IA zs a pany i E i det ahi TEL enopqretevoes ho daseustousevul 1 Lomo rf rdh 1843 NAAR out B A age 11 OCT 1944 gab our k n EBA Loi ten LOAD ak Le ge rr VERTICAL BLACK LINES REPETITIVE DEFECTS See Table 7 22 See Table 7 24 O oeatert JA 2A Pease 26 Scalable yis Typefaces Courier ma Courier zc Courier Dd ze Albertus XBS Wayi ce Ign amr wm LL o uus SSC rrr PARTIR CONCRA HORIZONTAL BLACK LINES STAINING See Table 7 23 See Table 7 25 7 21 Troubleshooting Image Formation Troubleshooting DROPOUT BACKGROUND SCATTER See Table 7 26 See Table 7 28 Laserdee qmm CHARACTER VOIDS BOTTOM PORTION BLANK See Table 7 27 See Table 7 29 7 99 Troubleshooting Image Formation Troubleshooting Dei SS Laser tr dL 300 DPI ACA 26 Scalable E G nenent pos iy Typefaces Coupfar ft Lovers Ur ar ag It lives Mo tetter Get L t Letter Gothic Bd en AND tertee fett 7 sr Ak OG Deg Antlaue Olive CG Tias Bd antique Give Bd CG Yes Ir Antique Olive It CG They Bd i Adema Ma nedd Albertus XB nenn Ma Wagi c4 ADEO ER Printer EM Information UNTER CUNHDULATI N conis Bn Jose Ze D KS terran Ss e ter Za Een umo PAGE PROTECT qu Sans Ser San Eum ENS Rene Er gj CES Laser er 4 BR 300 DPI GAGA
73. al Overview Image Formation System A set of lenses and mirrors focuses the horizontal sweeping beam through the laser beam access slot in the rear of the toner cartridge and onto the photosensitive drum Because the beam is sweeping the entire length of the drum and the drum is rotating the entire circumference of the drum can be covered The speed of the scanner motor which turns the scanning mirror and the speed of the main motor which turns the drum are synchronized and each successive sweep of the beam is offset 1 300th or 1 600th of an inch The beam can be turned on and off to place a dot of light every 1 300th or 1 600th of an inch in the horizontal direction This is how the printer achieves its 300 x 300 dpi or 600 x 600 dpi resolution At the beginning of each sweep before the beam reaches the drum the beam is reflected off the beam detect mirror The momentary pulse of light is sent to the DC Controller where it is converted to an electrical signal used to synchronize the output of data VDO for one sweep scan line This pulse referred to as the Beam Detect signal BD is used to diagnose problems with the laser diode or scanner motor After the writing station the drum surface has an invisible latent electrostatic image Portions of the drum not exposed to the laser are still at the uniform negative potential placed there by the primary charging roller but those portions exposed to light have been discha
74. al Overview Paper Feed System Paper Jam Detection The Input Paper Sensor PS1 Paper Exit Sensor PS3 and the Winding Paper Sensor PS4 detect when paper is moving through the printer see Figure 5 18 for sensor locations If a paper jam is detected the DC Controller immediately stops the printing process and causes a paper jam indication on the front panel A paper jam can be detected under any of the following conditions Power On Jams Paper is present under either PS1 PS4 or PS3 at power on Pickup Jams Paper does not reach and clear photosensor PS1 within a specified period of time For cassette feed the time period begins when the Paper Pickup Solenoid SL2 is energized for manual feed the time period begins shortly after PS1 is moved into the Manual Feed Sense Position position A under Input Paper Sensor Delay Jams Paper does not reach or clear a specific photosensor within a specified period of time 5 39 Functional Overview Basic Sequence of Operation Basic Sequence of Operation Standard Printer Operation The Formatter PCA and the DC Controller PCA share information during printer operation The DC Controller to Formatter Connector DC Controller J201 forms a link which operates as a serial data bus This allows printer status command information and dot image data to be passed between the two PCAs The following events take place during normal printer operation Table 5 3 Print Perio
75. an using alcohol 3 The Static Eliminator Strip is dirty oris Clean or replace the Static Eliminator not grounded allowing a static charge to Strip Use compressed air to clean see remain on the Static Eliminator Strip in Chapter 6 4 Fusing Assembly is defective The Replace the Fusing Assembly print will smear if the Fusing Assembly is not heated sufficiently to bond the toner image to the 5 DC Controller is defective The DC Con Jif anew Fusing Assembly does not troller regulates fusing roller temperature resolve the problem replace the DC Controller PCA 7 34 Troubleshooting Image Formation Troubleshooting Table 7 32 Image Skew POSSIBLE CAUSE RECOMMENDED ACTION 1 Paper is loaded incorrectly If the pa Remove paper from the tray and install per is not installed flush into the paper paper correctly Position the paper guide cassette a skewing problem will result _ correctly for the paper size being used 2 Bad Paper Lot Paper that is manufac Try a different paper lot see Media tured poorly or inconsistently or that has Specifications in Chapter 2 too smooth or too rough a surface tex ture can cause an image skew problem 3 Worn Pickup Oblique and or Registra tion Rollers Paper is not being picked up consistently 4 Beam to Drum Mirror adjustment is Refer to Beam to Drum Mirror required If the mirror has been re Adjustment later in this chapter to moved or th
76. and 0 2 of square Fusing Compatibility Overhead transparency material must be compatible with the heat and pressure of the fusing process Materials must not discolor melt offset material or release hazardous emissions when heated to 392 F 200 C for 0 1 second The flat paper path manual feed slot and rear face up delivery door is recommended for printing transparencies 2 15 Operating Requirements Media Specifications Storing Print Media Follow these guidelines when stacking and storing print media Store paper in its ream wrapper until ready to use DO NOT store cartons or reams directly on the floor place cartons on a pallet or on shelves DO NOT store individual reams in a manner that causes them to curl or warp along the edges Re wrap partially used packages of media before storing DO NOT stack more than six cartons on top of each other Stack each carton squarely on top of the one underneath Stack each carton upright DO NOT place anything on top of media regardless of whether the paper is packaged or unpackaged Store envelopes in a protective box to avoid damaging the envelope edges Keep stored media away from temperature and humidity extremes DO NOT store printed documents in vinyl folders which may contain plasticizers or expose the documents to petroleum based solvents Shipping Print Media When shipping print media through different environments plastic wrap
77. and closed The Scanner Motor M2 is controlled and monitored by the DC Controller and Laser Scanner PCAs The Scanner Motor operates during the Initial Rotation period and the Print period The Exhaust Fan Motor M3 is controlled and monitored by the DC Controller PCA The Exhaust Fan Motor operates for approximately 35 seconds during power ON and Standby It remains on during Initial Rotation Print and Last Rotation Periods 5 7 Functional Overview DC Controller Power System Power System on DC Controller PCA The ac dc and high voltage power supply circuits are all contained within the DC Controller PCA AC Power Distribution The ac power circuitry located on the DC Controller PCA supplies ac voltage to the DC Power Supply whenever the printer s power cord is connected to the ac power source The power switch must be turned ON in the LaserJet 4P 4MP A toner cartridge must be installed and the top door closed before voltage is supplied to the High Voltage Power Supply or Main Motor drive circuitry DC Power Distribution The DC Power Supply circuitry located on the DC Controller PCA generates 5 V dc and 12 V dc which is used as follows 5 V de Formatter PCA Photosensors DC Controller Circuitry Laser Scanner Assembly 12a V de High Voltage Power Supply a after switch Main Motor 12b V de Solenoids b before switch Laser Scanner Assembly to Fan The Power System Block Diagram is illustrated in Figu
78. area on the left side of the printer To print an engine test use a long object such as a pencil to press the engine test button see Figure 7 4 Do not use a metal object A single test page is printed Se 7 Engine Test Printout Figure 7 4 Engine Test Button and Printout LaserJet 4L 4ML 7 36 Troubleshooting Engine Test Printing an Engine Test LaserJet 4P AMP On the LaserJet 4P 4MP the printer s covers and the Formatter PCA must be removed prior to printing an Engine Test Since the covers will be removed the printer s safety interlocks must be defeated to provide power for running the Engine Test To defeat the interlocks and set up the printer for an Engine Test 1 Remove the printer cover the Formatter Shield and the Formatter PCA see Chapter 6 2 Install the paper cassette with paper loaded 3 Install a toner cartridge in the printer Lay a large sheet of thick paper over the toner cartridge and Laser Scanner Assembly to block out ambient room light this will prevent black streaks on the printed output 4 On the top of the printer use a piece of tape to hold down the Top Door Plunger shown in Figure 7 5 J Top Door Plunger P Tape plunger down 3 even with chassis Printer Chassis Top Rail S Top Rail to defeat j Plunger CG Assembly Body Paper Path Figure 7 5 Defeating the Top Door Plunger LaserJet 4P A
79. arts Index Numerical Parts Index DESCRIPTION 8 10 Claw Separation S Plate Solenoid Ground Plate Ground D P RB1 3332 000CN oor Top LJ 4P 4MP bring Cassette Side o WO IN IN I RB1 3338 000CN late End i co EM o 8 10 RB1 3341 000CN Tra Legal Cover Font LJ 4P AMP 83 Hinge Font Cover LJ 4P 4MP RB1 3356 000CN Button Lock LJ 4P 4MP RB1 3357 000CN Guide Lock Button LJ 4P 4MP 8 3 RB1 3365 000CN Shaft Holder LJ4P4MP Las 8 1 RBi 3402 000CN _ Spring Leaf LJ 4P AMP RB1 3404 000CN lGrounding Plate LJ 4P 4MP l Plate Grounding LJ 4P 4MP RB1 3798 000CN Spring Left Torsion LJ 4P 4MP RB1 3799 000CN Spring Right Torsion LJ 4P 4MP S T Co oo co GO CO CO oo RF5 0584 000CN tatic Eliminator Assembl RF5 0585 000CN RF5 0596 000CN oller Transfer Assembl 8 5 Co co joo Cn co J Parts Index 12 Parts index Numerical Parts index Beam to Drum Mirror Assembly LJ 4L 4ML RG5 0668 000CN Pickup Assembly LJ4L 4ML Front Oblique Roller Assembl Switch Cam Assembl Mount Transfer Assembly Left Mount Transfer Assembly Right RG5 0676 000CN _ Fuser Assembly 100 120V New RG5 0677 000CN Fuser Assembly 220 240V New co Io P 1 loo loo co P oo co j IG co ro IS ro ro Ion e FE IO j 3 no RG5 0681 000CN Fuser Delivery Assemb RG5 0682 000CN oller Lower O
80. aserJet LaserJet 4P 4MP ER A4L AML LEDs Display Panel Description amp Recommendations 53 XY ZZ ERROR An error has been found in RAM or ROM 1 Power cycle the printer If this doesn t clear the error 2 Power off the printer remove any additional memory then power back on If Data light is on the message clears replace the memory and all others cara are off 3 Replace the Formatter PCA LaserJet 4P 4MP Use the list below to decode the XY ZZ values X Hardware type 0 ROM 1 RAM Y Hardware device 0 On board RAM ROM 1 SIMM slot one 2 SIMM slot two 3 SIMM slot three ZZ Error Number 00 Unsupported memory 01 Unrecognized memory 02 Unsupported memory size 03 Failed RAM test 04 Exceeded max RAM size 05 Exceeded max ROM size 06 Invalid SIMM speed 07 SIMM reporting incorrect 08 SIMM RAM parity error Troubleshooting Printer Error Troubleshooting Table 7 12 Engine Error LaserJet LaserJet 4P 4MP 4L 4ML LEDs Display Panel Description amp Recommendations 55 ERROR The Formaiter and DC Controller are not communicating Power cycle the printer If this doesn t clear the message 1 Reseat the Formatter PCA into the DC Controller connector 2 Replace the Formatter PCA 3 Replace the DC Controller PCA 4 Replace the DC Controller connector Error light is on all others are off
81. box Saving Toner with EconoMode Toner cartridge life can be extended dramatically by using the EconoMode printing feature of the printer EconoMode can be turned on or off via the printer s front panel LaserJet 4P 4MP only through HP Explorer s Remote Control Panel or through a software application with the appropriate printer driver See Chapter 3 for information on the HP Explorer Remote Control Panel Notes EconoMode functions in portrait orientation only Some software applications may refer to this as draft mode Software settings always override front control panel selections LaserJet 4P 4MP 4 5 alcohol Pickup Feed D Roller Use a water dampened lint free cloth Registration Roller Use a dry lint free cloth Transfer Roller Use a dry lint free cloth DO NOT TOUCH with your fingers Beam to Drum Mirror Use filtered compressed air first If not effective use a lint free cloth or swab dampened with lens cleaner Fusing Pressure Roller Use a cloth or swab dampened with water Face up Deflector Use a cloth or swab dampened with water Anti Static Teeth Use compressed air Refer to Chapter 6 for removal procedure WARNING The Anti Static Teeth are extremely sharp Be careful Maintenance Cleaning Printer Components Cleaning Spilled Toner Defective toner cartridges can develop leaks In addition after a paper jam has occurred there may be some toner remaining on the roller
82. byte Optional maximum 1 Mbyte module Three 8 Mb SIMMs Two 8 Mb SIMMs 1 Envelope Capacity manual Internal Typefaces 26 PCL 45 PCL 35 PS 45 PCL 45 PCL 35 PS Standard Interfaces Parallel Bi tronics Serial 9 pin Serial 9 pin LocalTalk Parallel Bi tronics Parallel Bi tronics LocalTalk Parallel Bi tronics Power Control Intelligent On Off Intelligent On Off Control Panel 1 Button 4 LEDs 1 Button 4 LEDs 8 Keys 8 Keys 16 char display 16 char display 3 LEDs 3 LEDs Min Paper Size 3 x 6 75 inch 3x6 5 in 3x 5inch 3x5 inch using flat paper path 76 x 171 mm 76 x171 mm 76 x 127 mm 76 x 127 mm 1 See Accessories amp Supplies in Chapter 8 for option product numbers 2 Printer memory is optimized with Memory Enhancement Technology MEt 1 9 Product information Identification Identification Model and Serial Numbers The model number and serial numbers are listed on identification labels located on the rear of the printer The model number is alphanumeric such as C2003A for the HP LaserJet 4L The serial number contains information about the Country of Origin the Revision Level the Production Code and production number of the printer The rear labels also contain power rating and regulatory information as shown in Figure 1 1 POWER RATING rep TNE prod s wih CORK HEWLETT t00 120y P 21 CFR ci iA r PACKARD Tet 50 80 Hz WIR
83. cable connector to the right of the topmost SIMM slot on the Formatter PCA Figure 6 7 Figure 6 7 Control Pane Connector Location LaserJet 4P 4MP continued on next page 6 9 Removal and Replacement Cover and Doors 5 From the top of the printer remove the 4 self tapping screws Figure 6 8 callout 1 and one machine screw callout 2 6 From the front of the printer remove the one machine screw with star washer Figure 6 8 callout 3 etse siete E qe en m X eco sz Katze Figure 6 8 Removing the Printer Cover Screws LaserJet 4P AMP continued on next page a 6 10 Removal and Replacement Cover and Doors 7 Turn the printer around so that the back edge hangs slightly beyond the edge of the table Open the printer s rear door 8 Pull outward on the two rear cover tabs to release pressure and lift slightly Be sure to pull outward enough to clear the ac power receptacle Figure 6 9 callout 1 9 Reaching through the access hole Figure 6 9 callout 2 pull outward to clear the power switch 10 Turn the printer around and pull outward on the two front cover tabs to release pressure while lifting Figure 6 9 callout 3 Once all cover tabs are free and the ac input and power switch are clear lift the cover straight up carefully Be Pull outward on front cover tabs and lift cover off printer Push against printer chassis while pulling outward on rear cover tabs Reach t
84. calTalk I O LaserJet 4ML 4MP 5 15 Control Panel 5 16 LaserJet 4L 4ML 5 16 LaserJet 4P 4MP 5 16 Resolution Enhancement REt 5 17 Print Density Adjustment 5 17 EconoMode 5 18 Memory Management 5 19 Memory Enhancement technology MEt 5 19 Image Adapt LaserJet 4L AML 5 20 Page Protect 5 20 PJL Overview 5 21 continued on back Chapter 5 Contents Page 1 Image Formation System 5 22 Photosensitive Drum 5 23 Drum Sensitivity 5 24 Cleaning Stage 5 25 Conditioning Stage 5 26 Writing Stage 5 27 Developing Stage 5 29 Transferring Stage 5 31 Fusing Stage 5 32 Paper Feed System 5 33 Paper Movement Overview 5 34 Solenoids 5 35 Photosensors 5 35 Paper Out Sensor PS2 5 35 Input Paper Sensor PS1 5 36 Printing from the Paper Cassette 5 37 Manual Feed Printing 5 38 Small Media Rollers LaserJet 4P 4MP 5 38 Paper Jam Detection 5 39 Power On Jams 5 39 Pickup Jams 5 39 Delay Jams 5 39 Basic Sequence of Operation 5 40 Standard Printer Operation 5 40 General Timing Diagram 5 41 Contents Page 2 Chapter 5 Chapter Contents Removal and Replacement Removal and Replacement Strategy 6 2 Required Tools 6 3 User Installable Assemblies 6 4 Memory Upgrade LaserJet 4L 6 4 Memory Language SIMMs LaserJet 4P 4MP 6 5 Cover and Doors 6 6 Power I O and Memory Doors
85. cartridge and close the Top Door The start up sequence should rotate the drum enough to move the mark g Open the printer and inspect the gear that was marked in step 3 Verify that the mark moved If the mark did not move inspect the gear train to ensure that it is meshing with the toner cartridge gears If the printer s drive gears appear functional and the drum does not move replace the toner cartridge Note This test is especially important if refilled toner cartridges have been used F7 Af Troubleshooting High Voltage Power Supply Check High Voltage Power Supply Check The High Voltage Power Supply circuitry on the DC Controller PCA provides the necessary voltages for the printer s electrophotographic processes A method for verifying the high voltage system is given in the table below Table 7 34 High Voltage System Checks CHECKS ACTION 1 Toner cartridge connection points Visually inspect the three connection points on the underside right end of the toner cartridge If they are dirty or corroded clean the connections Clean using alcohol only If damaged replace the toner cartridge 2 High Voltage Connector Assembly The High Voltage Connector Assembly mounts on the DC Controller PCA and uses spring loaded pins to contact the toner cartridge see Figure 7 2 for locations Verify that the pins are not dirty or corroded and that the spring loading action is functional If the p
86. ceiving data control panel message 3 10 recoverable errors 7 7 recycling toner cartridges 2 7 refilled toner cartridges 2 7 related documentation 1 18 remanufactured assemblies 1 17 removal and replacement strategy 6 2 Beam to Drum Mirror 6 29 Control Panel LJet 4P 4MP 6 13 cover and doors 6 6 6 14 DC Controller Assembly 6 39 DC Controller Fuses 6 42 DC Controller PCA 6 43 DC Cont Scanner Connector 6 53 Fan 6 24 Feeder Guide Assembly 6 49 Formatter PCA 6 15 Formatter Shield 6 15 Front Oblique Roller 6 20 Fusing Assembly 6 30 Gear Train Assembly 6 17 High Voltage Connector 6 42 VO Door 6 6 Input Paper Sensor Arm 6 56 Laser Scanner Assembly 6 23 Lower Output Roller 6 38 Main Motor 6 19 Memory Door 6 6 memory upgrade 6 4 Paper Cassette Assembly 6 21 Paper Guide Top Oblique Roller 6 26 Pickup Assembly 6 47 Pickup Feed D Roller 6 46 Pickup Solenoid 6 41 Power Door 6 6 Power Switch 6 25 Printer Cover LJet 4L 4ML 6 7 Printer Cover LJet 4P 4MP 6 9 Rear Door 6 12 Small Media Roller 6 50 Static Eliminator Strip 6 51 Toner Cartridge Lever 6 52 Top Cover Switch Plunger 6 53 Transfer Roller and Guide 6 27 Transfer Roller Bushings 6 28 Upper Output Roller 6 37 repair philosophy 1 17 1 19 repetitive image defect ruler 7 46 required tools 6 3 requirements operating 2 1 2 16 site 2 2 2 3 space 2 3 reset cold 3 28 menu of 3 27 NVRAM 3 29 simple 3 26 resetting the printer 3 26 3 30 Index 5 Index Resolut
87. ck described later in this chapter or try a known good toner cartridge Replace the toner cartridge if necessa 3 Defective or contaminated Transfer Check roller installation and contact Roller Without a functional Transfer Perform the Half Self Test Functional Roller toner cannot be pulled from the Check described later in this chapter If photosensitive drum to the paper there is an image on the drum but not paper replace the Transfer Roller 4 Laser Scanner door not opening 1 Remove and re seat the toner properly cartridge 2 Check the Laser Scanner shutter door for proper operation If defective replace the Laser Scanner Assembly continued on next page F7 A Troubleshooting image Formation Troubleshooting ALL PAGES BLANK continued Check the pins and springs for functionality Clean if dirty replace is defective or missing 5 High Voltage Connector Assembly is defective The High Voltage Connector Assembly mounts on the DC Controller PCA and uses spring loaded pins to con tact the toner cartridge 6 DC Controller PCA is defective The Replace the DC Controller PCA DC Controller supplies the proper volt age to the High Voltage contacts Table 7 19 Black Page POSSIBLE CAUSE RECOMMENDED ACTION 1 Defective toner cartridge Replace the toner cartridge 2 Light is leaking into the printer Ensure all covers are in piace 3 High Voltage Connector Assembly is
88. ckup Feed D Roller Access to the Pickup Feed D Roller requires removal of the DC Controller Assembly The D Roller itself can be removed without removing the entire Pickup Assembly from the printer 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 and the DC Controller Assembly Figure 6 36 2 Lift upward on the pressure clip Figure 6 41 callout 1 and slide the D Roller off the shaft An Figure 6 41 Removing the D Roller To re install 1 Position the photosensor flag arm callout 2 out of the way 2 Apply pressure on the opposite end of the roller shaft callout 3 3 Push the D Roller onto the shaft until it clicks into place 4 After replacing the D Roller power on the printer without the paper cassette in place to cause the roller to rotate into the correct initial position 6 46 Removal and Replacement Bottom Assemblies Pickup Assembly 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly and Font Cartridge Bracket LaserJet 4P 4MP only Figure 6 23 and 6 16 and the DC Controller Assembly Figure 6 36 Tata Although not mandatory it may be more Note convenient to remove the Gear Train Assembly Figure 6 15 to provide easier access 2 Remove the plastic latch clip D Roll
89. ckup Feed D Roller solenoid arm in and rotate the D Roller down clear of the solenoid arm Figure 6 36 callout 4 5 Grasp the rails on either side of the DC Controller Assembly and lift the assembly out being careful not to catch the solenoid arm on the Pickup Feed D Roller continued on next page 6 39 Removal and Replacement Bottom Assemblies Note When removing the DC Controller Assembly there will be resistance where the connectors are attached on the left in Figure 6 36 A firm tug may be necessary to free the assembly MET IT v NIFT Figure 6 36 Removing the DC Controller Assembly To re install When reinstalling the DC Controller be sure to use a short length 6 mm machine screw at Figure 6 36 callout 3 A longer 10 mm screw will obstruct the Fusing Assembly Ensure that the PS1 Input Paper Sensor Arm Figure 6 51 and the PS2 Paper out Sensor Flag on the D Roller Assembly Figure 6 41 callout 2 are in their proper positions The Input Paper Sensor Arm should operate freely If either of these are not seated properly this will cause a continuous Paper Jam error condition BAN Removal and Replacement Botiom Assemblies Pickup Solenoid SL2 The Pickup Solenoid SL2 is located on the DC Controller PCA 1 Remove the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 and Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 and the DC Controller Assembly Figure
90. d Descriptions refer to Timing Diagram PERIOD TIMING PURPOSE From power ON power cord Clear the drum surface potential connection to the end of Main and clean the Transfer Roller Motor initial rotation STBY From the end of the WAIT orthe Maintain the printer in ready state Standby LSTR period until the input of the PRNT signal from the Formatter Or from the end of the LSTR period until power OFF INTR From the input of the PRNT signal Stabilize the photosensitive drum Initial from the Formatter until the laser sensitivity in preparation for Rotation diode intensity has been stabilized printing Also clean the Transfer Roller From the end of initial rotation until Form images on the the Scanner Motor stops photosensitive drum based on the INDO signal from the Formatter and transfer the image to paper LSTR From the primary voltage DC Deliver the last sheet of paper Last OFF until the Main Motor stops Also clean the Transfer Roller Rotation If another PRNT signal is sent from the Formatter the printer returns to the INTR period If not it returns to the STBY period 5 40 General Timing Diagram DEE 7 Dev e 211025 1 48 Trar Las UU Tt 7 nu Unit seconc STBY 30 0 variable E ai J Removal and Replacement Removal and Replacement Removal and Replacem
91. d High Voltage Shield 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 2 LaserJet 4L only If necessary remove the metal High Voltage Shield by lifting it out 3 Lift the Input Paper Sensor Arm out Figure 6 51 Removing ihe input Paper Sensor Arm To re install Be certain the Input Paper Sensor Arm and High Voltage Shield are aligned correctly when replacing Mis alignment or excessive force will break the delicate sensor arm 6 56 mm Troubleshooting Troubleshooting Troubleshooting Flowchart Troubleshooting Flowchart When ac power is first applied to the printer The exhaust fan is enabled 4L 4ML 35 seconds 4P 4MP continuous e The Main Motor rotates for about 5 seconds Lights illuminate for about 1 second then AC Power is applied 4L 4ML individually sequence front to rear to the printer 4P 4MP panel displays 05 SELF TEST then 02 WARM UP then 00 READY NOTE The fan will NOT rotate if any error condition is present Refer to Tables 7 1 through 7 15 to correct If no error or service message is being displayed the Top Door is closed and the toner cartridge is installed yet the fan does NOT rotate when ac power is applied to the printer verify the following e 1 P
92. data file or use the DOS Copy command to copy it to the printer Table 3 3 Example PJL Service Mode Commands PJL Command Ec96 12345X 9PJL PUJL SET SERVICEMODE HPBOISEID Enter Service Mode PJL SET PAGES 0 Set page count xxxxx PJL SET CRPAPER LETTER Sets cold reset page size Letter A4 PJL SET SKIPDEMO FALSE Skips demo PCL type page true false PJL SET DIAGNOSTICS OFF Sets diagnostics OFF ON for ISV use PJL SET SERVICEMODE EXIT Exits Service Mode PJL DEFAULT PAPER LETTER Selects user paper size default PJL RESET Performs PJL reset Ec96 12345X Exits PJL mode Eez Prints Self Test page FECE Resets the printer 3 29 Installation and Configuration PJL Software Commands 3 30 Maintenance Maintenance Service Checkpoints Service Checkpoints Figure 4 1 Service Checkpoints 1 Upper Fusing Assembly 6 Front Oblique Roller 2 Beam to Drum Mirror 7 Pickup Feed D Roller 3 Transfer Roller Assembly 8 Photosensitive Drum 4 Toner Cartridge 9 Fusing Pressure Roller 5 Registration Roller 10 Face Up Face Down Deflector Maintenance Life Expectancy of Consumables Life Expectancy of Consumables Always inspect the components listed in Table 4 1 for wear when servicing the printer Replace these components as needed based on printer failures or wear not strictly on usage Table 4 1 Life Expectancy of Consumables EST DESCRIPTION PART NO
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94. e the Formatter PCA 7 8 Troubleshooting Paper Path and Components Paper Path and Components DC Controller PCA g E g 8 e 8 5 E 5 S al 2 D G Ki 2 E ke tc HI o S gt gt E z ER E E s E um ite gt o T ur oa IINE NE N m mo 9g E zZ 3 Q GK S GO 9 SI c gt E a 2 amp z a E 5 a u Q 2 z 9 Z z x H ai m E z ai E oa K z z W Face Dow Q Output E m Rollers o o 2 Go a hr c Fusing unit ez GE ed Q Da Ps 4 Delivery X Roller Small Media 7 M Rollers 4P 4MP only Pickup D Roller REGISTRATION PAPER SENSOR signal PISNS Cassette Feed Paper Cassette Figure 7 1 Paper Path and Components PS1 Input Paper Sensor PS2 Paper Out Sensor PS3 Exit Paper Sensor PS4 Winding Paper Sensor Paper Path Input Paper Sensor PS1 Positions A Manual Feed Sense Position B Registration Sense Position C TOP Sense Position Troubleshooting DC Controller Diagram DC Controller Diagram A TO FRONT OF PRINTER HVPS J402 Circuitry Circuitry FU201 2 5A 125V Figure 7 2 DC Controller PCA Components J201 Formatter Connector J404 J202 Laser Scanner Connector VR301 J601 Main Motor Drive SW301 J103 Fusing Assy Heating Element SW201 and Thermoprotector J204 Fusing Assy Thermistor TH PS1 J206 Pickup Solenoid SL2 PS2 J207 Paper Feed Solenoid SL1 PS3 J401 Primary Charge Roller PS4 J402 Developer Roller FU201 Trans
95. e ech 14 19 THRU 30 32 36 Figure B 1 Parallel Cable Pin Assignments B 2 VO Information Serial Cable Pin Configurations LaserJet 4P 4MP Serial Cable Pin Configurations LaserJet 4P AMP The following table diagrams show the cable pinouts for the most common serial configurations DB 9 Serial Connection If connecting to a computer with a 9 pin serial port use the HP C2932A 9 9 pin M F serial cable or equivalent FEMALE DB 9 TO MALE DB 9 CABLE nc shell gt shell Figure B 2 Serial Pin Outs DB 9 to DB 9 DB 25 Serial Connection If connecting to a computer with a 25 pin serial port use the HP C2933A 9 25 pin M F serial cable or equivalent FEMALE DB 25 TO MALE DB 9 CABLE oN ee COMPUTER yam Figure B 3 Serial Pin Outs DB 25 to DB 9 B 3 1 O Information Connecting to LocalTalk Networks LaserJet 4ML 4MP Connecting to LocalTalk Networks LaserJet 4ML 4MP The printer does not come with a LocalTalk network cable Use a standard LocalTalk network cable and connector kit such as the HP LocalTalk Network Cable Kit part number 92215N You will need one connector kit for each printer on the network and another for each Macintosh computer on the network Connecting to the END of a LocalTalk Network Figure B 4 Connecting to the END of a LocalTalk Network 1 Disconnect the printer from its power source Insert the connector box cable into the LocalTa
96. e host computer through a Bi directional Parallel connection The printer can tell the host such things as the control panel settings and allow the control panel settings to be set from the host Dynamic I O switching LaserJet 4ML 4P 4MP allows the printer to be configured with a host on each I O The printer can receive data from more than one I O simultaneously until the buffer is full This can occur even when the printer is offline Note The Serial and LocalTalk I Os share the same softare interrupt Thus dynamic I O switching is limited to switching between the parallel interface and one other I O interface selected from serial and LocalTalk Context sensitive switching LaserJet 4ML 4P 4MP only allows the printer to recognize automatically the personalities PostScript or PCL of each host and configure itself to serve that personality Isolation of print environment settings from one print job to the next For example if a print job is sent to the printer in landscape mode the subsequent print jobs print in landscape only if they are formatted for landscape printing Functional Overview Image Formation System Image Formation System Laser printing requires the interaction of several different technologies such as electronics optics and electrophotographics to provide a printed page Each process functions independently and must be coordinated with all other printer processes The image formation process con
97. e is A4 When replacing Formatters whose default is set for A4 set the Customization Variable to A4 When the Customization Variable is set to A4 the Cold Reset procedure will always reset the paper size to A4 not to Letter To set the Customization Variable Enter the Service Mode as described in this section a 2 Press the REM ni to access the Service Menu 3 Press the D E to step through the menu until CH PRPERZLETTEE is displayed 4 Press the key to toggle between Letter and A4 paper 5 Press the DS key to save your selection 6 Press SUD to return the display to SERVICE MODE 7 Press E a second time to exit Service Mode Other Service Mode ad The other Service Menu items SHIP DEMO and E iS included for specialized purposes Y her item a to be changed from the default setting FALSE and OFF respectively the procedure is similar to that used for setting ihe page count or Cold Reset default described above Installation and Configuration Prnung a Self Test Printing a Self Test LaserJet 4L 4ML 1 Make sure the Ready light is on and all other lights are off If necessary reset the printer 2 Briefly press the front panel button LaserJet 4ML see Note below 3 After about 6 seconds the Data light blinks and the self test page starts to print see Figure 3 6 Usually only one page prints If fonts or macros have been downloaded a second page prints Nats LaserJet 4ML The pr
98. e right end mounting screw adjust the image to proper tolerances has been loosened the mirror needs to be readjusted 5 Manual feed skew problems Inspect all paper path rollers looking for wear cracks or glazing Replace the worn rollers Instruct customer to feed media against left side alignment guide and not to reinsert once the printer grips the media Table 7 33 Compressed Print POSSIBLE CAUSE RECOMMENDED ACTION 1 Toner cartridge bushings are too tight Replace the toner cartridge This may occur on refilled toner car tridges 2 Broken or worn gear Inspect and replace the worn gear or assembly 7 35 Troubleshooting Engine Test Engine Test The engine test print is used to verify that the print engine is functioning correctly The Formatter PCA is completely bypassed during an engine test This test is therefore very useful for isolating printer problems The engine test prints a full page of vertical lines down the entire printable area and is thus also useful for checking and adjusting registration Engine Test Button Location The engine test print button SW301 is located on the side of the DC Controller PCA see Figure 7 2 It is accessible through a hole in the Gear Train plate Printing an Engine Test LaserJet 4L 4ML On the LaserJet 4L 4ML the engine test button is accessible without removing the covers through the I O Door
99. ecifications 1 5 Tbl 1 4 Electrical Specifications 1 5 Tbl 1 5 Related Documentation 1 19 Tbl 2 1 Current Requirements Amps 2 2 Tb 2 2 Printer Operating Dimensions 2 3 Tb 2 3 Toner Cartridge Environmental Conditions 2 4 Tbl 2 4 Supported Media Sizes 2 9 Tbl 2 5 Selected Paper Specifications 2 11 Tb 2 6 Envelope Specifications 2 12 Tbl 2 7 Adhesive Label Specifications 2 14 Tbl 2 8 Transparency Specifications 2 15 Tbl 3 1 Front Panel Button Usage 3 11 Tbl 3 2 Menu of Resets LaserJet 4P AMP 3 27 Tbl 4 1 Life Expectancy of Consumables 4 3 Tbl 4 2 Cleaning Printer Components 4 6 Tbl5 1 Solenoids 5 35 2 Tb 5 2 Photosensors 5 35 Tbl 5 3 Print Period Descriptions 5 40 Tbl 7 1 Paper Out Error 7 7 Tbl 7 2 Paper Jam Error 7 8 Tbl 7 83 Door Open Error 7 9 Tbl 7 4 Memory Error 7 10 Tbl 7 5 Manual Feed 7 10 Tbl 7 6 Service Error 7 11 Tbl 7 7 Fuser Error 7 12 Tbi 7 8 Fuser Checks 7 12 Tbl 7 9 Beam Error 7 13 Tbl 7 10 Scanner Error 7 13 Tbl 7 11 RAM ROM Error 7 14 Tbl 7 12 Engine Error 7 15 Tbl 7 13 Main Motor Error 7 15 Tbl 7 14 Fan Error 7 16 Tbl 7 15 Formatter Error 7 16 Tbl 7 16 NVRAM Error 7 17 Tbl 7 17 Blank Display 7 17 Tbl 7 18 Blank White Page 7 24 Tbl 7 19 Black Page 7 25 Tbl 7 20 Faded Print 7 26 Tb 7 21 Vertical White Stripes 7 27 Tbl 7 22 Vertical Black Lines 7 28 Tbl
100. ee self tapping RFI shield screws Figure 6 12 callout 1 and one machine screw callout 2 5 The Control Panel PCA is located under the RFI shield Remove its 3 self tapping screws to replace the PCA To re install Before reassembly ensure that the control panel cable is properly routed within its cable guides 6 14 Removal and Replacement Left Side Assemblies Left Side Assemblies Formatter Shield and PCA The Formatter PCA is located under a metal RFI shield on the left side of the printer CAUTION Use proper ESD precautions when removing the Formatter PCA Avoid touching components and use an anti static bag for storage or shipping 1 Remove the Printer Cover 2 Remove the screws that hold the RFI shield in place and lift the shield off Figure 6 13 callout 1 for LaserJet 4L 3 Remove any remaining screws on the Formatter PCA Figure 6 13 callout 2 for LaserJet 4L Figure 6 13 Removing the Formaiter Shield and PCA LaserJet 4L shown 6 15 Removal and Replacement Left Side Assemblies 4 Grasp the Formatter PCA near the center and pull straight out the PCA is plugged into the DC Controller through the connector in the lower center area Note When replacing the Formatter PCA remove and transfer the Formatter to DC Controller Connector Extension all printers and the Switch Actuator LaserJet 4L 4ML to the new PCA Procedures are shown below 5 To remove the connector extensi
101. el cable 5 Remove the 4 self tapping printer cover screws Figure 6 5 callout 1 Figure 6 5 Removing the Pri nter Cover Screws LaserJet 4L 4ML continued on next page 6 7 Removal and Replacement Cover and Doors 6 With the Rear Door open pull the lower rear tabs outward away from the printer and lift upward slightly Figure 6 6 Figure 6 6 Releasing the Printer Cover Rear Tabs 7 Place a small object under the rear of the cover to keep it from snapping back in place Pull the front lower front tabs outward away from the printer chassis as in step 6 above 8 Grasping the front and rear lift the cover straight up being careful to not catch any other assemblies while lifting CAUTION Avoid holding the cover by the more flexible left and right sides Be careful to avoid catching the green Fuser Release Tab at the rear of the _ printer while lifting the cover off To re install When reinstalling the Printer Cover be sure the rear door is open Lower the cover straight downward to avoid catching any parts 6 8 Removal and Replacement Cover and Doors Printer Cover LaserJet 4P AMP 1 Unplug the power cord and interface cable s 2 Remove the toner cartridge and paper cassette CAUTION Steps 3 and 4 are critical to avoid damage to the SIMMs the Formatter PCA and cabling 3 Remove the SIMM access panel and any installed SIMM modules Figure 6 3 4 Unplug the front panel
102. ent Strategy Removal and Replacement Strategy This chapter documents removal and replacement of Field Replaceable Units FRUs only Exchange assemblies should be sent to SMO for repair Unless specifically stated otherwise these procedures apply to all four printer models LaserJet 4L 4ML 4P 4MP Replacement is generally the reverse of removal Occasionally notes are included to provide direction for difficult or critical replacement procedures WARNING CAUTION Note Unplug the power cord from the power outlet before attempting to service the printer If this warning is not followed severe injury may result Never operate or service the printer with the protective cover removed from the Laser Scanner Assembly The reflected beam although invisible can damage your eyes The printer contains parts that are electrostatic discharge ESD sensitive Always service printers at an ESD protected workstation To install a self tapping screw first turn it counter clockwise to align it with the existing thread pattern then carefully turn clockwise to tighten Do not over tighten If a self tapping screw hole becomes stripped repair of the screw hole or replacement of the affected assembly is required Always remove the toner cartridge and the paper cassette from the printer before removing or replacing printer parts Removal and Replacement Required Tools Required Tools 2 Magnetized Phillips Sc
103. er Paper Path PS1 Input Paper Sensor Input Paper Sensor PS1 Positions PS2 Paper Out Sensor A Manual Feed Sense Position PS3 Exit Paper Sensor B Registration Sense Position PS4 Winding Paper Sensor C TOP Sense Position 5 34 Functional Overview Paper Feed System Solenoids Table 5 1 Solenoids KS Paper Feed Solenoid Located in the Pickup Roller Assembly and Registration controls the registration rollers Pickup Solenoid Located on the DC Controller and controls the Pickup Feed D Roller Photosensors Table 5 2 Photosensors wl m Dem O PS1 Input Paper Sensor Four position photosensor Senses manual feed and paper at registration position Paper Out Sensor Senses empty paper cassette Exit Paper Sensor Senses paper exiting the fuser rollers Winding Paper Sensor Senses paper in the paper feed guide area Paper Out Sensor PS2 The Paper Out Sensor PS2 detects the presence of paper in the cassette If no paper is sensed in the cassette the Formatter displays the paper out indication on the front panel display panel message or Paper light The cassette must be reloaded before printing can resume 5 35 am Indicates that paper has not entered the paper path Input Paper WAIT Sensor PS1 STBY The Manual Feed Sense Position A indicates that paper has either been inserted into the manual feed slot or has been picked from the paper cassette and re
104. er bushing Figure 6 42 Use needle nose pliers to twist counter clockwise and pull it out through the access opening in the Gear Train Assembly CAUTION Be sure to remove the plastic latch clip as shown in Figure 6 41 before attempting to remove the D Roller or damage to the printer will result e Figure 6 42 Removing the Pickup Feed Roller Assembly side view continued on next page DA Removal and Replacement Bottom Assemblies 3 Lift upward on the pressure clip on the end of the Pickup Feed D Roller and remove the D Roller Figure 6 43 callout 1 This provides access to one of the mounting screws 4 Remove the 2 self tapping screws and lift the assembly straight out Figure 6 43 callout 2 Figure 6 43 Removing the Pickup Feed Roller Assembly bottom view To re install Rotate the Registration Roller slightly to allow the gears to mesh before seating the assembly CAUTION Do NOT force the assembly back into place Be sure the gears are meshed properly before replacing screws AR Removal and Replacement Bottom Assemblies Feeder Guide Assembly and High Voltage Shield 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 and the DC Controller Assembly Figure 6 36 2 Remove the 2 self tapping screws and the 1 machine screw from the Feeder Guide Figure 6 44
105. erfaces which are supported by the printers Use the subject index to quickly locate any information in the manual Fig 3 5 Fig 3 6 Fig 3 7 Fig 3 8 Fig 4 1 Fig 4 2 Fig 4 3 Fig 4 4 Fig 4 5 Fig 4 6 Fig 4 7 Fig 5 1 Fig 5 2 Fig 5 3 Fig 5 4 Fig 5 5 Fig 5 6 Fig 5 7 Fig 5 8 Fig 5 9 Sample Model and Serial Number Labels 1 3 External Assembly Locations LaserJet 4L 4ML 1 6 External Assembly Locations LaserJet 4P 4MP 1 7 Internal Assembly Locations all printers 1 8 LaserJet 4L Internal Assembly Locations 1 9 LaserJet 4P Internal Assembly Locations 1 10 Printer Space Requirements 2 3 Distributing Toner 2 6 Attaching the Help Labels LaserJet 4L 4ML 3 6 LaserJet 4L 4ML Front Control Panel 3 9 LaserJet 4P 4MP Front Control Panel 3 12 LaserJet 4P 4MP Menu Map 3 14 Service Mode Menu Map LaserJet 4ML 4P AMP 3 16 LaserJet 4L Self Test Page 3 20 LaserJet 4MP Service Mode Self Test Page 3 22 Engine Test Button and Printout LaserJet 4L 3 25 Service Checkpoints 4 2 Sample 5 Page Coverage 4 4 Paper Feed Area Jam 4 9 Clearing Jams from the Toner Cartridge Area 4 10 Clearing Jams from the Paper Guide 4 10 Releasing Paper from the Fusing Assembly 4 11 Clearing Jams from the Fuser Area 4 12 Printer Functional Block Diagram 5 2 DC Controller Loads 5 3 Top Cover Toner Cartridge Plunger 5 6 Power Supply Block Diagram 5 9 H
106. ery 68 SERVICE indicates NVRAM is full 1 Perform NVRAM Reset to clear NVRAM hold down US key during power on 2 Replace the Formatter PCA Table 7 17 Blank Display LaserJet LaserJet 4P 4MP 4L 4ML LEDs Display Panel blank Description amp Recommendations If the printer s lights remain off LaserJet 4L 4ML or the message display panel remains blank LaserJet 4P A4MP check the following 1 4L 4ML Printer is in Intelligent Off mode Press the front panel button or open the Top Door 2 Power is not supplied to the printer Check power cord connections and power source 3 Print an engine test print to determine if the print engine is functional If the test is successful replace the Formatter PCA 4 Check Fuses FU101 and FU201 on the DC Controller PCA Replace if necessary 5 Replace the DC Controller PCA 6 Replace the connector between the DC Controller and the Formatter Bl All lights off blank display 7 17 Troubleshooting Printer Error Troubleshooting Clearable Warnings LaserJet 4P 4MP A clearable warning indicates a transient condition in the printer The printer continues on line while the message is displayed in place of op FEAL A clearable warning appears each time the printer alters resolution or page protection this causes reconfiguration of memory or aborts a job due to an invalid or uninstalled pers
107. es to clear the buffer and stop the self test LaserJet AE AME 1 Press to take the printer off line The On Line tight goes off and the display reads op OFFLIME Press EM repeatedly until TEST MEHU is displayed Press ITEM until cOHT SELF TEST is displayed Press IA The display panel reads amp 4 SELF TEST After a few minutes a PCL Configuration self test page is printed see Figure 3 7 The self test page will print multiple copies continuing until the GREG or EE key is pressed 3 24 Installation and Configuration Engine Test Engine Test The engine test print can be used to verify that the print engine is functioning correctly The Formatter PCA is completely bypassed during an engine test This test is therefore useful for isolating printer problems The engine test prints a full page of vertical lines down the entire printable area and is thus also useful for checking and adjusting registration Note An Engine Test can be performed on the LaserJet 4L and 4ML with the printer covers in place as shown in Figure 3 8 The LaserJet 4P and 4MP require removal of the covers and the Formatter PCA Refer to Engine Test in Chapter 7 for the engine test procedure Engine Test Printout J Figure 3 8 Engine Test Button and Printout LaserJet 4L shown 3 25 Installation and Configuration Resetting the Printer Resetting the Printer
108. et 3 26 The Menu of Resets 3 27 The Cold Reset LaserJet 4ML 4P 4MP 3 28 LaserJet 4ML 3 28 LaserJet 4P AMP 3 28 PJL Software Commands 3 29 Contents Page 2 Chapter 3 Chapter Contents 4 Maintenance Service Checkpoints 4 2 Life Expectancy of Consumables 4 3 Toner Cartridge Life 4 4 Saving Toner with EconoMode 4 5 Cleaning Printer Components 4 6 Cleaning Spilled Toner 4 7 Clearing Paper Jams 4 8 Paper Jams in the Paper Feed Area 4 9 Paper Jams Inside The Printer 4 10 Paper Jams in the Paper Output Area 4 12 Chapter 4 Contents Page 1 Chapter Contents 5 Functional Overview Basic Printer Functions 5 2 DC Controller Power System 5 3 Print Engine Control 5 5 Laser and Scanner Drive 5 5 Paper Motion Monitoring and Control 5 5 Engine Test Microswitch SW301 5 7 Motors 5 7 Power System on DC Controller PCA 5 8 AC Power Distribution 5 8 DC Power Distribution 5 8 Overcurrent Overvoltage Protection 5 10 Intelligent ON OFF LaserJet 4L AML only 5 10 High Voltage Power Distribution 5 11 Formatter System 5 12 CPU 5 13 Read Only Memory ROM 5 13 Random Access Memory RAM 5 13 Non Volatile Memory NVRAM 5 14 Parallel Interface 5 14 High Speed Yes No 5 14 Advanced Functions On Off 5 14 Serial I O LaserJet 4P 4MP 5 15 Pacing Serial Modes of Operation 5 15 Lo
109. et printer users Helpful System Maps to the HP AUDIO TIPS recordings are available by fax through HP FIRST HP CompuServe Forum CompuServe members can download a variety of support materials including product data sheets software application notes and printer drivers for many popular software applications Members may also post and reply to questions in an interactive format To access the HP Forum type GO HPPER at any prompt For more information or to join CompuServe call 1 800 524 3388 Customer Information Centers For further technical assistance service authorized HP and dealer service personnel can contact the nearest Hewlett Packard Customer Information Center 1 800 752 0900 in North America Customer Support Center Assist Line The HP Customer Support Center 208 323 2551 is available to answer technical questions regarding setup configuration installation and operation of HP printers in the PC and Macintosh environments The CSC Assist Line is available weekdays from 7 AM to 6 PM Mountain Time Wednesdays until 4 PM Questions relating to operating systems such as MS DOS and UNIX your network configuration or network operating system cannot be answered by the Center and should be referred to your authorized reseller 1 21 p Operating Requirements Operating Requirements Site Requirements Site Requirements Operating Environment The environmental specifications listed in the Specif
110. f not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna e Increase the separation between the equipment and the receiver e Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help Any changes or modifications not expressly approved by Hewlett Packard could void the user s authority to operate this equipment Note Use of a shielded interface cable is required to comply within the Class B limits in Part 15 of FCC rules 1 15 Product Information VCCI Statement Japan VCCI Statement Japan The VCCI statement below is required in Japan It is similar to the FCC regulatory statement COMB S Sigg CENSO cog RI ku SEEGCETC Ae EE comEmEEMIEBY EUEAIETSIARE SERRE AERMHRAS VCCI RHicBALTEOET LOL kXE t27 4 7vUVavEmEiBHEwcEEUcCCIBRHCSEAt ZAZBHORALEATLERADETF FRI BAA Sito THE LY ARORVOELTFEWS Product Information Service Approach Service Approach Repair of the
111. f the lines are Refer to Table 7 24 next as well as the repeated ata consistent interval down Repetitive Image Defect Ruler Figure 7 9 the page this is a repetitive defect 7 989 Troubleshooting Image Formation Troubleshooting Table 7 24 Repetitive Defects When troubleshooting repetitive image defects use the Repetitive Image Defect Ruler supplied in Figure 7 9 to measure the distance between recurring defects POSSIBLE CAUSE RECOMMENDED ACTION 1 Toner cartridge is damaged The circumference of the photoconductive drum inside the toner cartridge is 75 mm 2 95 inches If the defect repeats at this interval the defect is associated with the drum Inspect the drum for scratches or damage Replace the toner cartridge 2 Dirty Rollers Any dirty roller in the pa Examine and clean rollers in the paper per path may result in a repetitive print Ipath refer to Cleaning Printer defect Components in Chapter 4 3 Fusing Assembly is dirty or defective The circumference of the lower fusing Pressure Roller is 47 mm 1 85 inches If the defect repeats at this interval the defect is associated with the Pressure Roller Clean the Fusing Assembly using alcohol If the problem persists replace the Fusing Assembly 4 Gears are worn causing slippage or Inspect the gears driving the toner jumping cartridge and the Fuser Replace the Gear Train Assembly if necessary 5 Paper does not meet specs The s
112. fer Roller FU101 J403 LL FU101 10A 125V PS1 PS302 L3 J801 Drum Ground Leading Edge Adjustment Engine Test Print Microswitch Top Door Toner Cartridge Microswitch Input Paper Sensor Paper Out Sensor Exit Paper Sensor Winding Paper Sensor DC Controller Power Supply Fuse Fusing System Circuitry Fuse 7 n Troubleshooting Printer Error Troubleshooting Printer Error Troubleshooting The printers use various means for conveying status and error messages as follows LaserJet 4L 4ML The HP LaserJet 4L 4ML printers are the first of the HP LaserJet family that do not use a display panel interface Information regarding printer status is conveyed by two methods 1 the printer s Control Panel lights and 2 feedback through the bi directional I O to display on the host computer The basic method of determining error messages uses patterns of lights on the front panel LEDs Printer messages are categorized into two basic types Recoverable Errors and Service Errors Both types are covered in the following sections Note Before troubleshooting a Service Error cycle the power to the printer to see if the error persists LaserJet 4P 4MP The LaserJet 4P 4MP uses an alphanumeric display panel for conveying status and error messages In addition as in the LaserJet 4L feedback is directed through the printers bi directional I O to display on the host computer 7 3 Troubleshooting Printer E
113. g from the front panel or through software A change in dc bias causes either more or less toner to be attracted to the drum which in turn either increases or decreases the print density The print density variation is approximately 10 see Figure 5 15 Both the primary and developer dc bias voltages are changed in response to the density setting Developing cylinder surface potential Drum surface potential pp eege A exposed area DC bias Y Drum surface potential unexposed area Figure 5 15 Developing Potentials Functional Overview Image Formation System Transferring Stage At the transferring station the toner image on the drum s surface is transferred to the paper A positive charge applied to the back of the paper by the transfer roller causes the negatively charged toner on the drum s surface to be attracted to the page The small radius of the drum combined with the stiffness of the paper causes the paper to peel away from the drum The Static Eliminator also helps separate the paper from the drum The Static Eliminator weakens the attractive forces between the negatively charged drum surface and the positively charged paper Without this help thin paper can wrap around the drum After separation the paper moves to the fusing station and the drum rotates to the cleaning and conditioning stations Static charge eliminator Transfer charging roller Figure 5 16 Transferring Stage 5 31
114. g Consumables 8 3 Common Hardware 8 4 Accessories and Supplies 8 5 Assembly Locations 8 7 Covers and Doors LaserJet 4L 4ML 8 8 Covers and Doors LaserJet 4P 4MP 8 10 Internal Components 1 8 12 Internal Components 2 8 14 Internal Components 3 8 16 DC Controller Assembly 8 18 Gear Train Plate Assembly 8 20 Paper Cassette LaserJet 4L 4ML 8 21 Paper Cassette LaserJet 4P AMP 8 22 Pickup Assembly 8 23 Fuser Assembly 8 24 Keyboard Overlay LaserJet 4P 4MP 8 26 Chapter 8 Contents Page 1 Appendix A Parts Index Appendix B VOlnformatn LO Information Subject Index g Product Information Product Information Printer Features Printer Features LaserJet 4L LaserJet 4ML LaserJet 4P LaserJet 4MP C2003A 020154 C2005A C2040A Text amp Graphics Resolution 300 dpi plus 300 dpi plus 600 dpi plus 600 dpi plus Res Enhancement Res Enhancement Res Enhancement 1 Res Enhancement technology REt technology REI technology DE technology RET Printer Language s Standard Enhanced PCL 5 PostScript Level 2 None Enhanced PCL 5 PostScript Level 2 None Enhanced PCL 5 Enhanced PCL 5 PS L2 with SIMM 44 Mb opt memory Monthly Usage pages Up to 8000 Up 1o 8000 Up to 8000 Up to 8000 Optional None Memory Standard 1 Mbyte yt 6 M
115. ge must be present and the top door must be closed before the printer can resume printing Top Door Plunger Printer Chassis Top Rail PM Toner Cartridge Plunger Assembly d So 7 Body Paper Path Transfer Roller DC Controller PCA Switch Actuator Top Door Microswitch SW201 Metal Switch Arm Figure 5 3 Top Cover Toner Cartridge Plunger amp Microswitch cutaway view Functional Overview DC Controller Power System Engine Test Microswitch SW301 Microswitch SW301 also located on the DC Controller is activated manually through an access hole in the Drive Train Assembly on the left side of the printer This switch causes the print engine to perform a self test diagnostic bypassing the Formatter PCA This test is useful for troubleshooting printer problems because it isolates the print engine from the Formatter The engine test prints a single page of vertical black lines which can also be used for adjusting print registration See Engine Test in Chapter 7 for more information Note The Engine Test print button can be accessed on the LaserJet 4L 4ML by opening the I O Door On the LaserJet 4P 4MP the printer covers and Formatter PCA must be removed first Motors The Main Motor M1 is controlled by the DC Controller PCA The Main Motor rotates during the Initial Rotation period following initial power ON the Print period or the Last Rotation Period or whenever the printer s top door is opened
116. ght open flames or ammonia fumes If the printer is placed near a window make sure the window has a curtain or blind to block any direct sunlight Install with enough space around the printer for proper access and ventilation see Figure 2 1 09 9 Operating Requirements Site Requirements Printer Space Requirements Figure2 1 X Printer Space Requirements Table 2 1 Printer Operating Dimensions maj w E Height Top 13 inches 33 cm 14 inches 35 cm Door open 2 3 Operating Requirements The HP 92274A Toner Cartridge The HP 92274A Toner Cartridge Toner cartridges contain components which are sensitive to light temperature and humidity Follow the recommendations in this section to ensure the highest quality and longest life of HP toner cartridges Table 2 2 Toner Cartridge Environmental Conditions CATEGORY TEMPERATURE HUMIDITY Operating 10 to 32 5 C 35 to 85 RH 50 to 90 5 F 20 to 40 C 15 to 90 RH 4 to 104 F Storage Conditions The toner cartridge is affected by its environment Packaging protects the toner cartridge from light and increases its storage life It is important to store the cartridge in its original packaging until the cartridge is ready to be installed in the printer When storing the toner cartridge in a warehouse or work area make sure the storage place meets the cond
117. he scatter can result particularly with Print Quality menu of the HP Explorer envelopes and heavier papers Remote Control Panel or through the Table 7 29 Bottom Portion of Page Blank MM MM MM M M E POSSIBLE CAUSE RECOMMENDED ACTION 1 Page too complex The printer can not Set Page Protect to ON or AUTO create the image fast enough to keep through the HP Explorer Remote Control pace with the print engine Panel 2 Not enough memory The page is too Add printer memory As an alternative complex for standard printer memory simplify the print job 3 Printing on legal size paper when soft Review software selection Ensure that printing is on selected size ware is specifying letter size This will also cause paper jams Troubleshooting image Formation Troublesnooting Table 7 30 Faulty Registration Symptoms of faulty registration are print images which are not skewed parallel to the paper path but which begin printing leading edge either too early or too late POSSIBLE CAUSE RECOMMENDED ACTION 1 Overloaded paper cassette If the cas Reload proper amount of paper sette is overloaded the Pickup Rollers squarely in the cassette Review paper may not pick the paper up correctly loading with the customer 2 Paper guide on the paper cassette ad Verify that the paper guide is adjusted for justed too tight If the guide is pushing the correct paper size and is
118. he two tabs are in place 56 96 Removal and Replacement Interna Assemblies Transfer Roller and Guide The Transfer Roller is located inside the top door under the toner cartridge The Printer Cover does not need to be removed to replace the Transfer Roller CAUTION Do not touch or otherwise contaminate the surface of the Transfer Roller Skin oils and other contaminants affect its electrical characteristics resulting in poor image transfer 1 Open the top door and remove the toner cartridge 2 Using a flat blade screwdriver gently pry under the left end to lift the roller shaft upward Figure 6 25 callout 1 continued on next page 6 27 Removal and Replacement Internal Assemblies 3 Lift the Transfer Roller and Guide slightly and slide toward the left to remove Do not lift the roller more than about 1 inch 2 5 cm before sliding it out of the right bushing 4 Pull the Roller shaft out of the clips on the Transfer Roller Guide to release the Transfer Roller from the Guide Note If replacing just the Transfer Roller Guide be careful not to lose the Transfer Roller gear It is only held in place by slight pressure and can fall off the Roller shaft To re install Install the right end first Ensure that the tabs are seated firmly in place below the plastic guide Figure 6 25 callout 2 and push the Transfer Roller into place Transfer Roller Bushings The Transfer Roller Bushings are loca
119. hen using other HP Explorer modules Installation and Configuration Using the Central Panel Using the Control Panel LaserJet 4L 4ML Control Panel Overview The HP LaserJet 4L 4ML printer s front control panel consists of 4 status lights and a front panel button situated on top of the printer Figure 3 2 LaserJet 4L 4ML Front Control Panel 3 9 Installation and AR Using the Contro Pane The LaserJet 4L 4ML Lights The LED lights provide a quick way to check the printer s status Ready Green STEADY The printer is ready to print a job from the paper cassette BLINKING If this light is blinking and the Data light is on steadily the printer is receiving or processing data Data Green STEADY If the Data light is on steadily and the Ready light is blinking the printer is receiving or processing data If the Data light and the Ready light are both on steadily there is unprinted data still in the printer Briefly press the front panel button to print the remaining data BLINKING The printer is in Manual Feed mode Either insert a sheet of paper into the manual feed slot or press the front panel button briefly to print from the paper cassette instead Paper Amber STEADY The paper cassette is empty or missing Add more paper BLINKING There is a paper jam Jam locations include the paper cassette under the toner cartridge or inside the printer s rear access door See Chapter
120. hrough access hole and pull outward to clear power switch P M Pull outward and lift slightly to clear ac power input Figure 6 9 Removing ihe Cover LaserJet 4P AMP To re install Ensure that the power switch is fully seated in its retaining slot When lowering the cover over the chassis be careful not to snag the parallel port bail lock left rear the ac power input right rear or the power switch Watch positioning of the front cover tabs and the control panel cable Re connect the control panel cable and replace any SIMM modules that were removed Removal and Replacement Cover and Doors Rear Door The Rear Door provides access to the fuser area The door is held in place by two flexible plastic tabs which mount into a groove on the rear of the Printer Cover 1 Remove the Printer Cover and turn it upside down 2 With the Rear Door open gently bend the tab inward and down to release Figure 6 10 Figure 6 10 Removing the Rear Door 6 12 Removal and Replacement Cover and Doors Control Panel LaserJet 4P AMP 1 Remove the Printer Cover and turn 1t upside down 2 Remove the 3 machine screws one with star washer Figure 6 11 callouts 1 and 2 3 Lift the Control Panel Assembly and unplug the connector from the PCA Figure 6 11 Removing the Control Panel Assembly LaserJet 4P 4MP continued on next page 6 13 Removal and Replacement Cover and Doors 4 Remove the thr
121. hts to communicate printer status to the user Light from the LEDs is transmitted through a single piece Light Pipe Assembly mounted on the inside of the printer cover Refer to Using the Control Panel in Chapter 3 and to Printer Error Troubleshooting in Chapter 7 for more information on the lights Front Panel Button The Formatter PCA includes a microswitch which is activated by the front panel button through a switch actuator which mounts on the surface of the PCA The single button is used for such functions as self test reset and displaying error codes Refer to Using the Control Panel in Chapter 3 for more information on the front panel button LaserJet 4P 4MP The Formatter PCA on the LaserJet 4P 4MP sends and receives printer status and command data via a Control Panel PCA which consists of an LCD display window and an 8 key keypad LCD Display Window The Formatter uses a backlit 16 character LCD display window in conjunction with three lights to communicate printer status to the user Display window messages can be configured in any of several languages 8 Key Keypad The eight keys on the keypad are used for a variety of functions such as switching online offline configuring the printer initiating self tests form feeds or resets and turning EconoMode on and off A keyboard overlay is available in any of several different languages see Chapter 8 for part numbers Functional Overview Formatter System
122. ications section of Chapter 1 must be maintained to ensure the proper operation of this printer Consider the following points before installing the printer e Install in a well ventilated dust free area Excess dust or smoke will contaminate the printer s Beam to Drum mirror affecting print quality Install on a hard flat and continuous surface with all four printer feet level Do not install on carpet or other soft surfaces Ensure adequate power supply circuitry Printer current requirements can be found under Specifications in Chapter 1 Lighting Flicker In an effort to reduce energy consumption the fuser is turned on only when needed during printing During standby mode the fuser is not kept warm When the printer is installed in a home the instant on fuser may cause some house lights to flicker when printing This phenomenon is seen in many instant on products such as copiers and will NOT affect printing nor will it harm the electrical system in any way To reduce a flicker effect plug the printer into a different outlet that may be on a separate circuit or try fluorescent lighting If possible add to the room s natural lighting Surge suppressers will not prevent flickering lights Install where there is stable temperature and humidity with no abrupt changes away from water sources humidifiers air conditioners refrigerators or other major appliances e Install away from direct sunli
123. ices and Radiologi cal Health 1 11 checkpoints service 4 2 CIC Customer Information Center 1 21 class 1 laser product 1 11 class B digital device 1 15 cleaning printer components 4 6 4 7 spilled toner 4 7 cleaning stage theory 5 25 clearable warnings LJet 4P 4MP 7 18 Index 1 ices DHHS 1 11 developing stage theory 5 29 DHHS 1 11 diagnostics service menu item 3 18 Direct Marketing Division DMO 8 3 DMO 8 3 documentation related 1 18 door open control panel message 3 10 drum rotation functional check 7 40 Index 2 Formatter error 60 67 SERVICE 7 16 Formatter error 70 71 ERROR 7 16 Formatter error 72 79 SERVICE 7 16 Formatter PCA 6 15 Formatter Shield 6 15 Formatter system theory 5 12 5 21 front assemblies 6 20 6 22 index front panel button clearing error states 3 10 overview 3 9 resuming after memory error 3 10 usage table 3 11 functions basic printer theory 5 2 fuser error 50 SERVICE 7 12 fuses DC Controller 6 42 Fusing Assembly 6 30 fusing stage theory 5 32 G Gear Train Assembly 6 17 H half self test functional check 7 39 hardware common 8 4 help labels 3 6 help labels installation 3 6 high speed parallel HO theory 5 14 High Voltage Connector Assembly 6 42 high voltage distribution theory 5 11 high voltage power supply check 7 41 HP ASAP Automated Support Access Program 1 20 HP AUDIO TIPS 1 21 HP Explorer drivers disk using 3 8 HP FI
124. igh Voltage Power Timing 5 11 Formatter Block Diagram 5 12 EconoMode vs Regular Print 5 18 Image Formation Block Diagram 5 22 Photosensitive Drum 5 23 Fig 5 10 Drum Surface Potential 5 24 Fig 5 11 Drum Cleaning 5 25 Fig 5 12 Primary Charging Roller 5 26 Fig 5 13 Image Writing 5 27 Fig 5 14 Image Development 5 29 Fig 5 15 Developing Potentials 5 30 Fig 5 16 Transferring Stage 5 31 Fig 5 17 Fusing Film and Pressure Roller 5 32 Fig 5 18 Printer Paper Path 5 34 Fig 5 19 Oblique Roller Paper Alignment 5 37 Fig6 1 Phillips vs Posidriv Screwdrivers 6 3 Fig 6 2 Memory Module LaserJet 4L 6 4 Fig 6 3 SIMM Access Panel LaserJet 4P 4MP 6 5 Fig 6 4 Power Access Door LaserJet 4L 4ML 6 6 Fig 6 5 Printer Cover Screws LaserJet 4L 4ML 6 7 Fig 6 6 Releasing the Printer Cover Rear Tabs 6 8 Fig 6 7 Control Panel Connector LaserJet 4P 4MP 6 9 Fig 6 8 Printer Cover Screws LaserJet 4P 4MP 6 10 Fig 6 9 Cover LaserJet 4P 4MP 6 11 Fig 6 10 Rear Door 6 12 Fig 6 11 Control Panel Assembly LaserJet 4P 4MP 6 13 Fig 6 12 Control Panel RFI Shield LaserJet 4P 4MP 6 14 Fig 6 13 Formatter Shield and PCA 6 15 Fig 6 14 DC Controller Connector amp Switch Actuator 6 16 Fig 6 15 Gear Train Assembly 6 17 Fig 6 16 Screw Tightening Sequence Example 6 18 Fig 6 17 Main Motor 6 19 Fig 6 18 Oblique Roller Assembly 6 20
125. igure 4 2 EE at Coverage EECEEERERERESE KEERSRESECEESE KR x E amp EREECEELE ERFERBEERBEEEZE TERRSSERREERRER EXXEZEPEEKEEZEKE LEEFER EREREERRRZEREE EEEZEREREEIRNE ZEFRERZIZEEZELK EEEPER ERBRE EECEE EFFE UKRPR PEEEEE BEERE ELEELE EERE EEFE Ser EXE SE RRRIS EZE ZERERE ZELETE Creare REEF ESETE CESELE SELES EEEFE PFEP LT CEE ERE ERERE BECER EELEE ERTZE EISE BREER EELEE FCEEER EZEEE EZEZERERERER REE EE ESEC LE TIEREITE FEREEREEITEKEE EECEF RIE EE ELEEE PEERE REE NEKCKERE CERI LE EBRE EIRE EEE EELE FIER KEREERS EREREIR EEE LERELERE ZE IZIE RER EZEKLI IREIR EEZEERE i rra CELES x ee BUMESE LERE ERREEEEEEEE LEARN ZEEEE EERE FEIER ETRRRE KKFEE EEEFE ER EEEEE REEERE inet E reese EKE REEE CELL EEEK ERE ETE KLE Se EERE EE EZES EYRE FE ELTE KEKE CEES EFE EBEE EEKEEET FEE EBELE CEE PEE BEX EEE EEE EES ZEILE HT EERE SLCREER FEER XE EE RP EER ESRB FAEEFEE EREE ECTS ELUR FRR PRR E EGE EE EEKEE EEEE EE KEER NIRE EE XREEE ER TELE aus BRERR RECTE KCEE TERE ZEE EERELERSELZEERE XEEEELELERZEER SELEEREFEELELE Figure 4 2 Sample 5 Page Coverage 4 4 Maintenance Life Expectancy of Consumables When regularly printing pages with less coverage such as short memos a toner cartridge should print over 3000 pages However if routinely printing very dense print the cartridge will not print a full 3000 pages Note For best results always use a toner cartridge before the expiration date stamped on the toner cartridge
126. ins are dirty clean using alcohol only if damaged replace the High Voltage Connector Assembly see Chapter 6 for procedure 7 41 Troubleshooting Paper Curl Paper Curl Paper curl is inherent to the laser printing processes and occurs when paper is subjected to heat Paper curl tends to relax as the paper cools while resting on a flat surface The specification for maximum paper curl when the paper is lying flat before print is 5 mm 0 2 inches Although paper curl cannot be totally eliminated some steps can be taken to lessen its impact as suggested in the following table Table 7 35 Causes of SEN C Curl POSSIBLE CAUSE RECOMMENDEDACTON ACTION 1 Paper Path Try using the face up paper delivery slot to shorten and simplify the paper path 2 Paper Surface The recommended printing surface of the page is usually marked on the end of a ream of paper 3 Paper Storing and Handling indicated by a small arrow and the phrase print this 4 Paper Type side first Load paper in the Paper Cassette with the recommended printing surface facing down ing up in the manual feed slot Over time paper assumes the characteristics of its storage environment in a humid environment paper absorbs moisture in a dry environment paper loses moisture Paper with higher moisture content will tend to curl more Evaluate the storage conditions of the paper All paper is manufactured differently different
127. ion Enhancement technology REt theory 5 17 resolution print 1 2 RFI statement 1 15 roller Small Media 6 50 S safety information 1 11 1 14 safety toner 1 14 saving toner EconoMode 4 5 scalable typeface list 3 21 ScanJet compatibility 1 2 scanner error 52 ERROR 7 13 screws length DC Controller 6 40 screws used in printer 8 4 self test continuous 3 24 engine 3 25 printing 3 19 3 24 printout LaserJet 4L 3 21 printout LaserJet 4P 4MP 3 23 sequence of operation theory 5 40 Serial I O theory 5 15 serial number 1 3 service approach 1 17 1 19 service checkpoints 4 2 service errors 7 11 service mode 3 15 3 18 shipping damage 3 3 shipping print media 2 16 SIMMs memory language 6 5 simple reset 3 26 site requirements 2 2 2 3 skew adjustment 7 44 skip demo service menu item 3 18 SL2 Pickup Solenoid 6 41 Small Media Roller assembly 6 50 small media rollers theory 5 38 software package printing 3 8 solenoid Pickup SL2 6 41 solenoids theory 5 35 Specifications printer 1 4 1 5 printer dimensions 1 4 adhesive labels 2 13 electrical 1 4 envelope 2 12 media 2 8 2 16 performance 1 4 transparency 2 15 speed print 1 2 Static Eliminator Strip Assembly 6 51 status lights functions 3 10 storage conditions toner cartridge 2 4 Index 6 storing print media 2 16 strategy removal and replacement 6 2 supplies and accessories 8 5 8 26 SW201 top door toner cartridge microswitch 5 6 SW301
128. ion in case of a catastrophic overcurrent condition in the DC Controller power supply regulation circuitry Intelligent ON OFF LaserJet 4L 4ML only This printer feature conserves power by shutting down all the printer s front panel LED status lights after a 15 minute period of inactivity The printer retains all printer settings and downloaded fonts and macros while in Intelligent Off mode The lights power ON instantly when any of the following occur A file is printed The front panel button is pressed The printer s top door is opened Paper is inserted into the manual feed slot A paper cassette is removed or installed Note The printer will not enter Intelligent Off mode if there is a printer error Functional Overview DC Controller Power System High Voltage Power Distribution The High Voltage Power Supply circuitry located on the DC Controller PCA applies an overlap of dc and ac voltage to the primary charging roller and the developing cylinder This circuit also applies a positive or negative dc voltage to the transfer charging roller according to the instructions from the CPU on the DC Controller PCA This circuit also controls the image density by changing the primary ac voltage and the developing ac bias according to the image density signal from the Formatter Figure 5 5 shows the timing of the high voltage power supply Power ON V WAIT PRINT signal PRNT VERTICAL SYNC signal
129. iscussion The names of major printer parts and assemblies are Capitalized Bold is used for emphasis particularly in situations where italic type would be confusing Italic type is used to indicate related documents or emphasis COMPUTER type indicates text as seen on a computer monitor DISPLAY type indicates text as seen on the printer s 16 character LCD display panel LaserJet 4P 4MP only LAZNA indicates keys on a computer keyboard or on the printer s control panel LaserJet 4P 4MP only Examples include BIJ and 173 Notes contain important information set off from the text CAUTION Caution messages alert you to the possibility of damage to equipment or loss of data WARNING Warning messages alert you to the possibility of personal injury A detailed matrix of printer features is followed by general information on the four printer models Specifications major assembly locations safety and regulatory information are all included The chapter ends with a discussion of the service and repair philosophy along with useful information on obtaining technical help Recommendations pertaining to the physical location of the printer and consumables are followed by general print media specifications including specifications for paper envelopes labels and transparencies Chapter 3 provides the step by step installation and setup procedure along with detailed information on using the Sontrol Panel for each printer model
130. it Sensor Flag E ri aure 6 32 Removing ike Lower Delivery Guide and Exit Sensor Flag Ei i wt To re install Be certain to install Exit Sensor Flag into its groove Figure 6 32 6 35 Removal and Replacement Rear Assemblies Connector Assembly Fuser Entrance Guide 1 Remove the connector wires from each end of the Connector Assembly Figure 6 33 callout 1 2 Gently squeeze the cable clip tabs using needle nose pliers and slide the cable clip out of the frame Figure 6 33 callout 2 3 Remove the 1 machine screw Figure 6 33 callout 3 4 Slide the Connector Assembly toward the cable clip location and lift out Figure 6 33 Removing the Fuser Connector Assembly To re install Be certain to correctly align the wires that run inside of the Connector Assembly to avoid damage 6 36 Removal and Replacement Rear Assemblies es Output Roller Assembly Remove the Printer Cover 2 Using a flat blade screwdriver release the two sided tabs from each end of the Roller Assembly Figure 6 34 3 Lift the Upper Output Roller Assembly out to remove CAUTION Be careful not to lift one end of the shaft more than about 1 2 inch 1 cm before both ends have been released as this will break the shaft Figure 6 34 Removing the Upper Output Roller Assembly 6 37 Removal and Replacement Rear Assemblies Lower Output Rollers There are four separate output rollers located direct
131. itions specified in Table 2 2 Note The expiration date of the toner cartridge is stamped on the cartridge box This date allows for up to 21 2 years after manufacture Operating Requirements The HP 92274A Toner Cartridge Storing Opened Toner Cartridges Because the cartridge does not have a shutter to cover the laser beam access slot it should be kept inside the printer until empty Toner cartridges which have had the toner sealing tape removed are also more vulnerable to environmental extremes such as high humidity If the toner cartridge must be removed from the printer always store the cartridge e Inside the protective bag in which it was originally packaged e na dark cabinet away from direct sunlight Correct side up and in a horizontal position not standing on end e Inatemperature between 10 and 35 C 50 95 F e Away from ammonia or other organic solvent fumes CAUTION Never ship the printer with a toner cartridge installed Excessive vibration during shipping can cause toner to leak contaminating the printer Never expose the toner cartridge to direct sunlight or to room light for more than a few minutes Bright light and direct sunlight can permanently damage a toner cartridge 2 5 Operating Requirements The HP 92274A Toner Cartridge Toner Cartridge Handling Suggestions e Before installing a cartridge distribute the toner evenly by rotating the cartridge back and forth five to
132. le 92274A C2024A C2024 69001 R75 0010 0000N R75 2010 000CN 8120 6177 RF5 0690 000CN Cleaning Brush RB1 3389 000CN Velcro Adhesive Cleaning Brush Holder C206XA SIMMs 36 bit are also supported however C303XA SIMMs 32 bit are recommended This PostScript SIMM is not compatible with any other printers 4P only ce o m D n3 oO o li o5 65 GA RS I9 gt ir IC 8 5 Parts and Diagrams Accessories and Supplies This page intentionally blank 8 6 Parts and Diagrams Accessories and Supplies Fusing Assembly See Figure 8 12 DC Controller Assembly See Figure 8 7 Gear Train Assembly See Figure 8 8 Pickup Assembly See Figure 8 11 Paper Cassette See Figure 8 9 amp 8 10 Formatter Assembly See Figure 8 4 Figure 8 1 Assembly Locations LaserJet 4L shown 8 7 Covers and Doors LaserJet 4L 4ML only Figure 8 2 8 8 Parts and Diagrams Accessories and Supplies Table 8 2 Covers and Doors LaserJet 4L 4ML only REF PARTNO DESCRIPTION RG50685000N 1 Cover Assembly Door lO 2 RB1 2978 000CN Door Power RB1 3131 000CN 2 Shatt Top Door Hinge Button Lock Guide Lock Button amp RBi3134000CN 1 Spring Left Torsion Spring Right Torsion 8 RF5 0597 000CN Cover Main Front Panel Button Light Pipe Washer SE Ring 9 RBi31360000CN 2 CRG Pressure Piece Door B
133. lk port of the printer 2 Insert one end of the cable into the new connector box If the connector box is not self terminating insert a terminating resistor into the connector box S Insert the other end of the cable into the last connector box on the network Remove the terminating resistor if necessary gt e Reconnect the printer to its power source IO Information Connecting to LocalTalk Networks LaserJet 4ML 4MP Connecting to the MIDDLE of a LocalTalk Network Figure 8 5 Connecting to the MIDDLE of a LocaiTalk Network 1 Disconnect the printer from its power source Insert the new connector box cable into the LocalTalk port of your printer 2 Insert one end of the new cable into the connector box 3 Place the other end of the new cable next to a connector box on the network 4 Unplug one cable from the connector box on the network Figure B 6 Connecting to the MIDDLE of a LocalTalk Network continued 5 Insert the new cable into the connector box on the network 6 Insert the cable you removed from the network into the new connector box Then reconnect the printer to its power source B 5 LO Information Connecting to LocalTalk Networks LaserJet 4ML 4MP B 6 Index Index 0 9 50 SERVICE Fuser Error 7 12 51 ERROR Beam Error 7 13 52 ERROR Scanner Error 7 13 53 ERROR RAM ROM Error 7 14 55 ERROR Engine Error 7 15 57 ERROR Main Motor Error 7
134. locked into too tightly against the paper it may be position Note that too loose a setting delayed in being pulled into the printer may cause image skewing 3 Paper does not meet specs The sur Try a different paper lot see Media face of the paper may be too smooth for Specifications in Chapter 2 the Pickup and Feed Rollers to correctly feed paper into the printer 4 Registration adjustment is required If the top of the page does not begin printing within the proper distance from the leading edge of the paper then a registration adjustment is required Refer to Leading Edge Adjustment later in this chapter Replace the defective gear if available or the Drive Train Assembly Inspect all paper path rollers looking for wear cracks or glazing Replace the worn rollers 5 Worn or broken drive gears If any gear within the drive train or paper path becomes excessively worn or dirty er ratic paper movement can result 6 Worn Pickup Oblique and or Registra tion Rollers Paper is not being picked up consistently 7 33 Troubleshooting Image Formation Troubleshooting Table 7 31 Smeared Print ductivity or surface finish of the media being printed may not work correctly with the electrophot hi 2 Dirty Fusing Rollers Toner build up Remove and inspect the Fusing can cause the print on a page to smear Assembly for excessive toner build up Cle
135. ly below the Upper Output Roller Assembly Each roller is held in place by three pressure tabs 1 Remove the Printer Cover 2 Remove the Upper Output Roller Assembly Figure 6 34 3 Push either the left or right tab inward tilt the Output Roller and lift upward to remove Figure 6 35 Use the same procedure for all four rollers Wee espesor Figure 6 35 Removing the Lower Output Rollers 6 38 Removal and Replacement Bottom Assemblies Bottom Assemblies DC Controller Assembly The DC Controller Assembly is located on the bottom of the printer The PCA is protected by a metal shield assembly and is mounted to a plastic base The Formatter PCA and Fusing Assemblies are connected directly into the DC Controller and must be removed prior to removal of the DC Controller Assembly 1 Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 and the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 CAUTION Failure to remove all the above components before removing the DC Controller will result in printer damage 2 Remove the 2 screws that attach the grounding springs to the Gear Train Assembly Figure 6 36 callout 1 3 Remove the 5 self tapping screws and the 1 machine screw from the bottom of the DC Controller Assembly Figure 6 36 callouts 2 and 3 Do not remove the Pickup Solenoid screw crossed circle in Figure 6 36 4 Push the Pi
136. mbly Locations Figure 1 4 1 Face Down Output Rollers 2 Upper Fusing Assembly 3 Laser Scanner Assembly 4 Primary Charging Roller 5 Beam to Drum Mirror 6 Developing Cylinder 7 Toner Cartridge 8 Registration Roller 9 Oblique Rollers Internal Assembly Locations all printers 10 Pickup Feed D Roller 11 Transfer Roller Assembly 12 Photosensitive Drum 13 DC Controller PCA 14 Paper Cassette 15 Fusing Pressure Roller 16 Face up Delivery Roller 17 Face Up Face Down Deflector Product Information Product Overview Figure 1 5 shows the location of assemblies visible from the top of the LaserJet 4L printer with the printer cover removed Figure 1 5 LaserJet 4L Internal Assembly Locations 1 Transfer Roller 2 Paper Guide Top Oblique Roller 3 Front Oblique Roller 4 Switch Actuator 5 Formatter PCA 6 Main Motor 7 Gear Train Assembly 8 Fusing Assembly 9 Lower Output Rollers Face Down 10 Upper Output Rollers Face Down 11 Fan FM1 12 Beam to Drum Mirror 13 Laser Scanner Assembly 1 0 Product Information Product Overview Figure 1 6 shows the location of assemblies visible from the top of the LaserJet 4P printer with the printer cover removed Figure 1 6 LaserJet 4P Internal Assembly Locations 1 Transfer Roller 9 Fusing Assembly 2 Paper Guide Top Oblique Roller 10 Lower Output Rollers Face Down 3 Front Oblique Roller 11 Upper Output Rollers Face Down 4
137. n Page Count Firmware Datecode Image Adapt Used Control Errors 26 Scalable Typefaces HEWLETT PACKARD Univers Bd Univers Md It Univers Bd it Univers Md Cd Univers Bd Cd Univers Md Cd it Univers Bd Cd ft Antique Olive Antique Olive Bd Antique Olive it Albertus Md Albertus XBd Wingdings ca ELORO 0 6 ROMANE Courier 1024K bytes 19920927 NO None LaserJet 4L Self Test Page showing default settings 2 90 Installation and Configuration Printing a Seif Test The LaserJet 4L Self Test Fields 1 Printer Features List This area can be used to check for graphics print quality 2 Scalable Typeface List Samples of the printer s internal scalable typefaces Note Removing ac power returns items 3 through 12 to factory default settings shown in Figure 3 6 3 Paper Handling Shows the current paper settings 4 Print Quality Adjustment Current settings for print density and Resolution Enhancement REt 5 Memory Configuration Settings for Image Adapt Page Protection and Auto Continue 6 EconoMode Setting of this toner saving feature 7 Font Selection Current default printer font settings 8 RAM size Shows the total amount of installed printer memory including added optional memory Use to verify proper memory installation 9 Page Count Shows approximately how many pages have been printed since the last power on This value is returned
138. nal Components 2 REF PARTNO DESCRIPTION RF5 0596 000CN Roller Transfer Assembly E 1 Beam to Drum Mirror Assembly RG5 0667 000CN LaserJet 4L 4ML RG5 0802 000CN LaserJet 4P 4MP RG5 0674 000CN 1 Mount Transfer Assembly Left 4 RG5 0675 000CN 1 Mount Transfer Assembly Right 6 RG5 0683 000N 1 RolerUpoerOutputAssembly Switch Plunger Assembl SES Transfer Guide Assembl Bushing Transfer Guide 9 RG5 0764 000cN 1 Motor Main Assembl XA9 0495 000CN ncludes drive gear 8 15 Parts and Diagrams Accessories and Supplies G32 A Internal Components 3 Figure 8 6 8 16 E bs 1 SUUA UUULR PIE UH RS5 2232 000CN cue Britt vr del Sensa RG5 0670 000CN 1 Iron Oblique Roller Assembl Guide Feeder Assembly RG5 0671 000CN LaserJet 4L 4ML RG5 0793 000CN LaserJet 4P AMP RS5 0364 000CN Laser Scanner Assembly RG5 0662 000CN LaserJet 4L 4ML New C2003 69005 LaserJet 4L 4ML Exchange RG5 0800 000CN LaserJet 4P 4MP New C2005 69005 ge XA9 0653 000CN Screw M3X6 XB4 7401 209CN RB1 3392 000CN 1 Dust Cover Foam Rubber Parts and Diagrams Accessories and Supplies DC Controller Assembly Figure 8 7 8 18 Parts and Diagrams Accessories and Supplies Table 8 7 DC Controller Assembly mr meng av DESCRIPTION Plate Solenoid Ground 1F Plate Ground High Voltage Connector Assembl 1 DC Co
139. ning Stage After the drum is physically cleaned it must be conditioned This process consists of applying a uniform negative charge on the surface of the drum with the primary charging roller located in the toner cartridge The primary charging roller is coated with conductive rubber with an ac bias applied to erase any residual charges and maintain a constant drum surface potential In addition a negative dc bias is applied by the charging roller to create a uniform negative potential on the drum s surface The amount of dc voltage is modified by the print density setting Primary charging roller Photosensitive drum Figure 5 12 Primary Charging Roller 5 96 Functional Overview Image Formation System Writing Stage At the writing station the laser beam is used to discharge the photosensitive drum s negative potential by focusing laser light onto its surface This creates a latent electrostatic image which later is developed into a visible image Laser light is produced by a small modulated laser diode The beam created by the diode shines onto a rotating polygonal mirror As the mirror rotates the beam reflects off the mirror and sweeps the page from left to right see Figure 5 13 Bi tronics HO Formatter PCA BD VDO DC Controller PCA BDI NDOUT APCSH SCNON Laser Scanner PCA Scanning Mirror Focusing lens Reflecting mirror Photosensitive drum Figure 5 13 Image Writing 5 21 Function
140. nkled nicked or otherwise damaged Envelopes with a peel off adhesive strip or more than one fold over flap to seal must use adhesives compatible with the heat and pressure of the printer s fusing process When printing envelopes always use the flat paper path manual feed slot and the rear face up delivery door CAUTION To prevent severe printer damage do not use envelopes having windows clasps snaps or synthetic materials Table 2 5 Envelope Specifications Paper used for envelope construction must meet the requirements in the table under Media Selection Pap Guidelines er Basis Weight 20 to 24 pound 75 to 90 g m2 single thickness ish 3 3 to 5 5 mils 0 084 to 0 14 mm single thickness Curl Pre printed Envelopes must lay flat with no more than 0 2 in 5 mm curl across the entire surface Finishing Envelopes must not have any adhesive exposed to the printer They must be folded accurately within 0 04 1 mm There must be no more than two thicknesses of paper anywhere along the leading edge All folds must be wel scored and sharply creased and construction must be tight not baggy Envelopes must not be stuck together with excess seam gum 100 chemical wood pulp and or cotton fiber Must not scorch melt offset or release hazardous emissions when heated to 392 F 200 C for 0 1 second Operating Requirements Media Specifications Adhesive L
141. nt the job as requested install additional memory The job was printed at 600 dpi with page protection set to A4 To print the job as requested install additional memory W5 JOB 300 LTR W6 JOB 300 A4 W7 JOB 300 LGL W8 JOB 600 OFF W9 JOB 600 LTR WO JOB 600 A4 7 18 Troubleshooting Image Formation Troubleshooting Image Formation Troubleshooting This section illustrates some image defects and their possible causes Since there are many variables in the printing process it is possible to encounter image defects that are not illustrated below If you find a defect that is not illustrated record the probable cause along with the printing environmental conditions and save a copy of the defect for future reference Troubleshooting Image Formation Troubleshooting HEWLETT PACKARD 100 NPI 26 Mealahbie i SW eo apen ae Typefaces rers to Iren TE mines Bers Memory Ennancement reme md ae anna pA Aa omn engm BE CA ique Clive intique tive Ba Ante DAYE Artus Pl H Albertus XBd f conoMode B ss Me e n D Printer Information BLANK PAGE FADED PRINT See Table 7 18 See Table 7 20 We tt noe vida Fah VK seopan E E pond E i te Ki E m m i wi 4 i BLACK PAGE VERTICAL WHITE STRIPES See Table 7 19 See Table 7 21 7 On Troubleshooting Image Formation Troubleshooting LL E LILI
142. nterface VO Controller Controller ROM Figure 5 6 Formatter Block Diagram Functional Overview Formatter System The Formatter PCA receives ASCII data from the Bi Tronics Interface and converts it into a dot image The image orientation portrait or landscape and the font type are both selected When the scan buffer is full or when a Form Feed command is received the Formatter sends a PRINT signal to the DC Controller The DC Controller synchronizes the Image Formation System with the Paper Feed System and signals the Formatter to send the print image data The Formatter sends the print image data dots in the form of a VIDEO signal and the printing process begins CPU The Formatter PCA incorporates the following microprocessors e LaserJet 4L Motorola 68000 16 MHz e LaserJet 4ML Intel 80960KA 18 5 MHz e LaserJet 4P Intel 809608A 16 MHz e LaserJet 4MP Intel 80960KA 18 5 MHz 32K instruction cache Read Only Memory ROM Besides storing microprocessor control programs the ROM stores the dot patterns of internal character sets fonts Random Access Memory RAM The RAM stores printing and font information received from the host system and can also serve to temporarily store a full page of print image data before the data is sent to the print engine see Page Protect RAM memory capacities for each printer are shown under Printer Features in Chapter 1 Note that adding memory will not inc
143. ntil lights except when all are flashing in lights are lit sequence Service Error Clears all data from memory including unprinted data downloaded fonts and macros Resets printer to factory default settings Wake Up Press button fortwo All off Takes the printer out of seconds Intelligent Off mode Continue Press button fortwo Anyrecoverable Allows the printer to seconds error code see recover and continue Chapter 7 printing the job Press button for two DATA and READY Print remaining data in seconds light on steady printer memory Press button fortwo DATA light Override manual feed to Override _ seconds blinking print from paper cassette Hold down button to IA lights on steady Press the button to display code display service light pattern Use Chapter 7 to determine the problem and solution 3 11 Installation and Configuration Using the Control Panel LaserJet 4P 4MP Control Panel Overview The HP LaserJet 4P 4MP printer s front control panel consists of a 16 character backlit LCD display an 8 key control panel and 4 LED status lights situated on top of the printer To access a primary key function such as On Line Form Feed or Menu just press the appropriate key To access secondary key functions Reset EconoMode and use the EIN key For example to access the reset function of the key press EX
144. ntroller PCA 100 120V RG5 0753 000CN LaserJet 4L 4ML New C2003 69003 LaserJet 4L 4ML Exchange RG5 0822 000CN LaserJet 4P 4MP New LaserJet 4P 4MP Exchange DC Controller PCA 220 240V LaserJet 4L 4ML New LaserJet 4L 4ML Exchange LaserJet 4P 4MP New LaserJet 4P 4MP Exchange Pick up Solenoid SL2 Fuse FU101 100 120V Fuse FU101 220 240V Fuse FU201 100 120V ONLY 2005 69003 RH7 5092 000CN WD1 0288 000CN VD7 0643 151CN 3 RG5 0767 000CN C2003 69004 RG5 0823 000CN C2005 69004 6 1 VD7 0522 501CN 8 19 Parts and Diagrams Accessories and Supplies Figure 8 8 Gear Train Plate Assembly Table 8 8 Gear Train Plate Assembly PART NO DESCRIPTION Gear Train Plate Assembly EH 1 RG5 0684 000CN LaserJet 4L 4ML RG5 0791 000CN LaserJet 4P AMP Spring Leaf LaserJet 4L AML LaserJet 4P AMP Screw w star washer M3X6 RB1 3125 000CN RB1 3402 000CN XB2 7300 606CN 8 20 Parts and Diagrams Accessories and Supplies Figure 8 9 Paper Cassette LaserJet 4L 4ML Table 8 9 Paper Cassette LaserJet 4L 4ML el mene av eem mmeoot ocN 1 Universal Paper Cassette 8 Rs52229000CN 1 Jang Compression Smal 9 RsseesooocN 1 omg Compression Large Parts and Diagrams Accessories and Supplies Figure 8 10 Paper Cassette LaserJet 4P 4MP Table 8 10 Paper Cassette LaserJet 4P 4MP PART NO DESC
145. ntroller Power System The DC Controller PCA is responsible for coordinating all print engine activities The DC Controller drives the laser coordinating print data from the Formatter PCA with the image formation process The DC Controller shares machine status information with the Formatter PCA so that proper diagnostic messages are displayed The DC Controller also provides both ac and de power supply and distribution circuitry Figure 5 2 shows the various DC Controller loads UM DC Controller PCA 4P Only Laser Scanner Assemb CPU Formatter PCA Sensors and Solenoids DC Power Supply Charging Rolle High Voltage IDeveloping Rolle Power Supply Bia ET X Transfer Roller AC Power Supply 4 _ Fusing Assembl e o Power Switch e 4P 4MP only Front Conrtrol Panel Figure 5 2 DC Controller Loads 5 3 Functional Overview DC Controller Power System In summary the following systems and functions are controlled by the DC Controller Print Engine Control e Laser and Scanner Drive e Paper Motion e Microswitches Top Door and Engine Test e Motors Main Drive Scanner Fan e Power System e AC Power Distribution e DC Power Distribution e High Voltage Power Distribution e Overcurrent Overvoltage Protection e Intelligent On Off LaserJet 4L 4ML only 5 4 Functional Overview DC Controller Power System Print Engine Control Laser and Scanner Drive Based on information recei
146. ocedure above prints a n demo page only on the LaserJet 4ML To print PCL and PostScript configuration pages on the LaserJet 4ML press and hold the front panel button down for at least 10 seconds until the Data light is ON and the Ready light is blinking Five pages will be printed including font sample pages LaserJet 4P 4MP 1 Press TET to take the ee off pue The On Line light goes off and the display reads 88 OFFLINE 2 Press TEST repeatedly until TEST MENU is displayed 3 Press TM to display SELF TEST 4 Press DIEA The display panel reads 85 SELF TEST After a few minutes a PCL Configuration self EE page is printed see Figure 3 7 3 19 Installation and Configuration Printing a Self Tesi Figure 3 6 shows a self test printout for the LaserJet 4L It lists all factory default settings Larener 4 O Figure 3 6 300 DPI N eenen Phanceneni TECHNO EconoMode Bi Tronics d Memory Enhancement ogc e HP Explorer Enhanced PCL 5 pa Courier Courier Bd Courier It Courier Bd It Letter Gothic Letter Gothic Bd Letter Gothic It OG Times CG Times Bd CG Times ft CG Times Bd it oronet Univers Md PRINTER CONFIGURATION COPIES ORIENTATION LINES OF TEXT PAPER SIZE IER FEED IMAGE ADAPT PAGE PROTECT AUTOCONTINUE ECONOMODE FONT NUMBER FONT SOURCE FONT HEIGHT FONT PITCH SYMBOL SET DEFAULT TYPEFACE RAM size Power o
147. ompression 8 6 Spring Compression Small Spring Font Door Torsion LJ 4P 4MP Fuse FU101 220 240V 87 Fuse FU101 100 120V Screw Main Motor Screw Top Door LJ 4L 4ML Screw Top Door LJ 4P AMP Screw M3X6 8 6 Screw w star washer M3X8 8 12 M4x10 Screw XB47401 209CN M4Xi2Screw Scanner Lasel M3x6 Solenoid Screw E Clip LJ 4L 4ML Parts Index 15 Parts Index Numerical Parts Index Parts Index 16 Appendix B i TO Information 10 Information Bi Tronics Parallel Cable Information Bi Tronics Parallel Cable Information The Bi Tronics parallel interface is compatible with Centronics parallel interfaces To take advantage of its enhanced capabilities such as bi directional communication between the computer and printer faster transmission of data and auto configuration of printer drivers the customer must have e Support in software applications for these features e A parallel cable with the correct pin configuration see below Parallel Cable Pin Configuration For best results use the C24542D cable or equivalent Most existing parallel cables support Bi Tronics communication but some might have incompatible pin assignments CAUTION Ensure that all power and interface cables on the printer and host computer are properly grounded in compliance with local codes Signal Name Printer Pin IBM Port Pin x nSTROBE DATA 1 1 2 3 4 5 6 7 8 9 10 11 12 13 NOS WMH OOO MOR WN e
148. on squeeze the tabs on either side and pull the Extension straight out the rear of the PCA Figure 6 14 callout 1 6 LaserJet 4L 4ML Squeeze the tabs on the Switch Actuator and pull it straight out from the back side of the Formatter PCA Figure 6 14 callout 2 Figure 6 14 DC Controller Connector amp Switch Actuator LaserJet 4L shown 6 16 Removal and Replacement Left Side Assemblies Gear Train Assembly The Gear Train Assembly is located on the left side of the printer under the Formatter PCA The steps and pictures here are for the LaserJet 4L 4ML The LaserJet 4P 4MP is slightly larger but very similar 1 Remove the Printer Cover and Formatter PCA Figure 6 13 2 Loosen do not remove the 2 upper self tapping Main Motor screws Figure 6 15 callout 1 3 Through the access holes Figure 6 15 callout 2 remove the 2 screws securing the Gear Train grounding springs small diameter machine screws with captive star washers These screws are connected to the DC Controller Assembly 4 Remove the 6 self tapping screws Figure 6 15 callout 3 5 Pull the Gear Train Assembly straight out to remove Keep the gear side of the assembly face up gears are held in place by light pressure only and may fall off if the assembly is tilted Figure 6 15 Removing the Gear Train Assembly LaserJet 4L shown continued on next page 6 17 Removal and Replacement Left Side Assemblies To re install
149. onality or insufficient memory Message Displayed Meaning W1 IMAGE ASSIST The printer received a graphics print file that was too complex to print at the requested resolution The printer automatically processed the file in the highest resolution possible with the memory installed Add additional memory to print the file at full resolution Check the printout for loss of data or print qualit W2 INVALID PERS The job was not printed because the requested personality such as PostScript was not installed Install the language in which the files are sent together with enough memory to support that language W3 JOB ABORTED The printer was forced to abort the print job because there was not enough installed memory to support the printer language used W4 JOB 300 OFF The job was printed at 300 dpi with page protection off To print the job as requested install additional memory The job was printed at 300 dpi with page protection set to letter To print the job as requested install additional memory The job was printed at 300 dpi with page protection set to A4 To print the job as requested install additional memory The job was printed at 300 dpi with page protection set to legal To print the job as requested install additional memory The job was printed at 600 dpi with page protection off To print the job as requested install additional memory The job was printed at 600 dpi with page protection set to letter To pri
150. or Input Paper Sensor Printing from the Paper Cassette Printing from Manual Feed Paper Jam Detection 5 33 Functional Overview Paper Feed System Paper Movement Overview The paper feed system picks print media automatically from the paper cassette or accepts it from the manual feed slot and delivers it to the image formation system at precisely the right time The system then feeds the media to the fusing station and delivers the finished product to the output position either the face down output tray on top of the printer or through the face up delivery slot at the rear of the printer The output path is user selectable by turning the paper path knob on the rear of the printer Figure 5 18 shows the possible paper paths and locations of the various solenoids photosensors and rollers DC Controller PCA gnal ignal DELIVERY PAPER SENSOR signal POSNS WINDING PAPER SENSOR si POSNS PICK UP SOLENOID DRIVE si CPUD MAIN MOTOR DRIVE signal Face Dowi REGISTRATION SOLENOID DRIVE signal PAUSD Manual Feed Paper c Path 6 2 N 2 x Ei E E D Ki E eo Va 2 WwW Ka D D E Lu 9 lt o REGISTRATION PAPER SENSOR signal PISNS Photosensitive Drum Fusing unit We ae A Ce m Face Up T P Ges A een Delivery Oblique Roller sm i Roller Zus only GEN ae Roller Cassette Feed j f Paper Cassette Paper Path Figure 5 18 Print
151. other local phone numbers Note Parts that have no reference designator or part number are not field replaceable parts and cannot be ordered through SMO 8 3 Parts and Diagrams Common Hardware Common Hardware Table 8 1 Common Fasteners Used in the Printer machine screw Phillips Formatter PCA 0515 2419 machine screw Formatter PCA 0515 2251 Phillips machine Fuser Assembly XA9 0654 000CN screw with captive star washer Feeder Gde Ground XA9 0653 000CN Gear Train Ground XB2 7300 606CN Fuser Ent Guide XB2 8300 809CN G 32 in drawings XB4 7401 007CN UE Phillips screw Laser Scanner XB4 7401 209CN G 17 in drawings XB4 7300 809CN 6mm 8mm 10mm 12mm M3 M4 pe pev peu iE 4 9 O 8 4 Parts and Diagrams Accessories and Supplies Accessories and Supplies The following items are available through your local authorized HP dealer To find a dealer near you or if your dealer is temporarily out of stock call the HP Customer Information Center 800 752 0900 Note Refer to Ordering Related Documentation in Chapter 1 for documentation part numbers HP Toner Cartridge 1 Mb memory upgrade LaserJet 4L only New 1 Mb memory upgrade LaserJet 4L only Exchange 1 Mb Memory SIMMs LaserJet 4P 4MP only 2Mb Memory SIMMs LaserJet 4P 4MP only 4Mb Memory SIMMs LaserJet 4P 4MP only 8Mb Memory SIMMs LaserJet 4P 4MP only 2049 67901 Adobe PostScript Level 2 SIMM LaserJet 4P only ib
152. ower at the receptacle is good Yes 2 The fan is fully seated into its connector at the Scanner Assembly 3 The Scanner is fully seated into its connector on the DC Controller PCA 4 Fuses FU101 and FU202 on the DC Controller are NOT open Does the exhaust fan operate when power is first applied If no error or service message is being displayed the Top Door is closed and the toner cartridge is installed yet the Main Motor does NOT rotate when ac power is applied to the printer verity the following 1 Motor is correctly mounted on chassis and seated into DC Controller connector 2 Replace the Main Motor 3 Replace the DC Controller PCA Does the Main Motor rotate for about 5 Seconds continued on next page Troubleshooting Troubleshooting Flowchart Do the Formatter LEDs illuminate Yes Perform an Engine Test Is the Engine Test image being S printed clearly ls the Self Test image being printed clearly Performa frontpanel Self Test If the Control Panel is not functional 1 Verify Formatter PCA is fully seated into the DC Controller PCA 2 Replace the Formatter PCA 3 Replace the DC Controller PCA No Refer to the section Image Formation Troubleshooting later in this chapter If the engine test produces a clear print image yet a clear Self Test is not generated by the front panel self test procedure replac
153. pen Close door and reset printer 3 Jam removed but printer not reset Perform front panel reset 4 Transfer Roller Guide Plate not installed correctly all 3 tabs must be in position See Chapter 6 for installation procedure 5 Stuck or broken flags sensors Note where the leading edge of the paper is to determine which paper sensor may be causing the jam Ensure sensor flags rotate freely Replace flags or associated assemblies if broken or if they remain stuck 6 Paper fragment under oblique rollers top or front Remove rollers and clear out paper 7 Main Motor faulty Power up the printer and observe if the stacker rollers rotate If not replace the Motor 8 Stuck or Faulty Gears in Gear Train Replace Gear Train 9 Toner cartridge not rotating Refer to Drum Rotation Functional Check later in this chapter 10 Transfer Roller Gear missing or broken Replace the Transfer Roller 11 Stuck or broken solenoids Replace solenoid or associated assembly 12 DC Controller PCA faulty Replace PCA 13 Software related for example program in letter but feeding legal size paper Change the software paper size setting or feed the designated size Paper light is blinking All other lights are off Troubleshooting Printer Error Troubleshooting Table 7 3 Door Open Error LaserJet LaserJet 4P AMP or AL 4ML LEDs Display Panel Description amp Recommendations
154. printer normally begins with use of the printer s internal diagnostics in conjunction with the troubleshooting procedures in Chapter 7 Once a faulty part is located repair is accomplished generally by assembly level replacement of Field Replaceable Units FRUs Some mechanical parts may be repaired at the sub assembly PCA component replacement is not supported by HP Part numbers for all FRUs are located in Chapter 8 of this manual Exchange Program HP offers remanufactured assemblies for some selected parts These are identified in Chapter 8 and can be ordered through HP s Parts Direct Ordering or Parts Center Europe PCE Ordering Parts Field replaceable part numbers are found in Chapter 8 of this manual Replacement parts may be ordered from HP s Parts Direct Ordering or Parts Center Europe PCE Adresses and phone numbers for both organizations are also found in Chapter 8 Ordering Consumables Consumables may be ordered directly from Hewlett Packard The phone numbers for ordering consumables are found in Chapter 8 1 17 Product Information Service Approach Ordering Related Documentation Table 1 5 shows where to order related documentation Phone numbers for the various sources are PDO Parts Direct Ordering A9 FM H e PCE Parts Center Europe 49 7031 14 2253 e HP s Distribution Center HPD 303 353 7650 U S only Product Information Service Approach Table 1 5 Related Documentation eme
155. ps tilt upward and lift out carefully CAUTION SIMM modules must be removed prior to removing the Printer Cover to avoid damage Figure 6 3 Removing the SIMM Access Panel LaserJet 4P 4MP To re install SIMM module can be installed in any available slot Sequence is irrelevant Install with the small notch toward the left To re install the access panel hold it in place and lift firmly upward on the thumb grip Figure 6 3 callout 2 to snap into place 6 5 Removal and Replacement Cover and Doors Cover and Doors Power I O and Memory Doors LaserJet 4L 4ML The Power Door is located on the right side of the printer The I O Door and Memory Door are on the left side refer to Figure 1 2 Some doors are not hinged and are removed simply by opening Others such as the Power Door have a small hinge tab which holds the door in place To remove the Power Door 1 Open the door to a 90 degree angle 2 Push the upper tab down slightly and tilt the door out Figure 6 4 Figure 6 4 Removing the Power Access Door LaserJet 4L 4ML 6 6 Removal and Replacement Cover and Doors Printer Cover LaserJet 4L 4ML 1 Remove the Power Door and unplug the power cord Figure 6 4 2 Remove the toner cartridge and paper cassette 3 Remove any optional memory card Figure 6 2 CAUTION Step 3 is critical to avoid damage to the memory card the Formatter PCA and the DC Controller 4 Unplug the parall
156. re 5 4 5 8 Functional Overview DC Controller Power System Power supply Main switch Im em pm e raz D i ER 4P 4MP Only i I 5 Fuse Za FUIOU ag o4 Noise D Fusing EE fiter Heater Fuse Him Relay SEN 12b V Door switch Seteg 12V SW201 Hg Noise 412a y voltage 12b V Voltage filter ipd ofo power i before switch dud M Supply 12a V Voltage circuit Lo circuit TT f TE i CURI after switch cation swt circuit 1128 V T Main Regulator Main motor motor JJ Main Sub Supply drive Motor power circu ce 12a V Ovetvoltage 2 Solenoid overcurrent detection 12b V circuit Laser scanner 45V a power 45V Fan motor supply yA circuit Sensor DV power supply circuit x Formatier PCA Power circuit for monitoning input CPU sw voltage i Figure 5 4 Power Supply Block Diagram 5 9 Functional Overview DC Controller Power System Overcurrent Overvoltage Protection The 12V dc and 5V dc power circuits each contain an overcurrent overvoltage protection circuit which automatically shuts off the output voltage when an overcurrent condition occurs due to a short or abnormal voltage on the load side The protection circuit automatically resets after the input power is cycled OFF then ON Fuse FU101 provides overcurrent protection for the Fusing System circuitry Fuse FU201 not present on 220 240 V units provides protect
157. re the continuity between connectors J103 1 and J103 2 on the Fuser see Figure 6 29 Chapter 6 for location It should be approximately 29 Ohms If the thermal fuse is open replace the Fusing Assembly 2 Thermistor wire open 3 Thermal Fuse 7 19 Troubleshooting Printer Error Troubleshooting Table 7 9 Beam Error LaserJet LaserJet 4P 4MP ios 4L 4ML LEDs Display Panel Description amp Recommendations h c3 51 ERROR Power cycle the printer If this doesn t clear Ro the error ga 1 Reseat the Laser Scanner Assembly into the Scanner DC Cable Assembly HE 2 Replace the Laser Scanner Assembly Data and Error 3 Replace the DC Controller PCA lights are on 4 Replace the Scanner DC Cable and all others Assembly are off Table 7 10 Scanner Error LaserJet LaserJet 4P AMP SE gt AL AML LEDs Display Panel Description amp Recommendations 52 ERROR Power cycle the printer If this doesn t clear the error 1 Ensure condensation from moving the printer from a cold to warm environment hasn t occurred Allow the printer 6 hours to Paper and Er acclimate to the warm room ror lights are on 2 Reseat the Scanning Assembly and all others 3 Replace the Laser Scanner Assembly are off 4 Replace the DC Controller PCA 5 Replace the Scanner DC Cable Assembly 7 13 Troubleshooting Printer Error Troubleshooting Table 7 11 RAM ROM Error L
158. rease I O buffer space or print speed Note The LaserJet 4P 4MP printers support 32 bit SIMMs C303XA series as well as the 36 bit SIMMS C206XA series used in earlier LaserJet family printers 5 13 returns to zero and the printer returns to factory default settings LaserJet 4ML AP 4MP 256 bytes of NVRAM is used on these printers to store I O and print environment configuration information The contents of NVRAM are retained when the printer s power is turned off or disconnected As in other HP LaserJet printers downloaded fonts and macros are saved in conventional RAM and are lost when power is turned off Parallel Interface The Formatter PCA receives incoming ASCII data through its Bi Tronics interface connector The Bi Tronics I O provides high speed two way communication between the printer and the host allowing the user to change printer settings and monitor printer status from the host computer The Bi Tronics I O is compatible with the Centronics parallel interface standard Note Refer to Parallel Cable Pin Configuration in __ Appendix B for parallel pin assignments High Speed Yes No The High Speed Yes No configuration item is user selectable The default setting Yes allows the I O to run at the higher speeds supported by most newer PCs Ifthe mode is set to No the parallel interface runs at the slower but compatible mode for older PCs Advanced Functions On Off
159. rewdriver 6 inch shaft e Small flat blade Screwdriver o Small Pair Needle Nose Pliers All screws used in the printer are Phillips head screws which require a 2 size Phillips screwdriver Figure 6 1 shows the difference between a Phillips and a Pozidriv screwdriver Note that the Phillips tip has more beveled surfaces CAUTION A Posidriv screwdriver will damage the printer s screw heads Use Phillips only Phillips Posidriv Figure 6 1 Phillips vs Posidriv Screwdrivers 6 3 Removal and Replacement User Installable Assemblies User Installable Assemblies Memory Upgrade LaserJet 4L The small access door on the left side of the printer allows access to the memory connector on the Formatter PCA CAUTION Memory modules must be removed prior to removing the Printer Cover to avoid possible damage to the memory the Formatter PCA or the DC Controller 1 Open the Memory Door 2 Pull outward on the small handle to unplug the memory assembly and remove Figure 6 2 Removing the Memory Module LaserJet 4L 6 4 Removal and Replacement User Installable Assemblies Memory Language SIMMs LaserJet 4P 4MP The SIMM slots are under an access panel on the left side of the printer Place the printer on a firmly supported flat surface 1 Push downward forcefully on top of the access panel to release its clips from the main Printer Cover Figure 6 8 callout 1 2 Remove any SIMM modules release side cli
160. rged to ground to form the latent electrostatic image 5 28 Functional Overview Image Formation System Developing Stage The developing station develops the latent electrostatic image into a visible image on the drum The developing unit consists of a metallic cylinder that rotates around a fixed magnetic core inside the toner cavity Toner is a powdery substance made of black plastic resin bound to iron particles which is attracted to the magnetic core of the cylinder A rubber blade brushes the toner on the developing cylinder to a uniform thickness The toner particles obtain a negative surface charge by rubbing against the developing cylinder which is connected to a negative dc supply The negatively charged toner is attracted to the discharged grounded areas of the drum exposed to laser light and repelled from the negatively charged non exposed areas An ac potential is applied to the developing cylinder to decrease the attraction between the toner and the magnetic core of the cylinder and to increase the repelling action of toner against the areas of the drum not exposed to laser light This ac potential improves density and contrast see Figure 5 14 Developing cylinder DC bias Figure 5 14 image Development 5 29 Functional Overview Image Formation System The de bias of the developing cylinder is adjusted to change the force of attraction between the toner and drum by changing the print density settin
161. rror Troubleshooting Priority of Errors Each error has a priority in relation to the others If there is more than one error condition at the same time the highest priority error will be displayed The priority of errors is Service Errors Door Open No Toner Cartridge Paper Jam Paper Out Memory Error Manual Feed a 9v Wd Recoverable Errors Recoverable Errors are displayed on single front panel lights without pressing the front panel button Recoverable errors do not require a service call unless the error persists after the suggested remedy has been implemented Recoverable errors are listed in Tables 7 1 through 7 5 Table 7 1 Paper Out Error LaserJet LaserJet 4P 4MP nat 4L 4ML LEDs Display Panel Description amp Recommendations PC LOAD paper size 1 Paper Cassette is empty or missing 2 Add paper and or insert cassette 3 Reseat the cassette d Check if Paper Out flag PS2 bottom of printer adjacent to the Pickup D Roller is broken or movement is hindered Unstick or replace the Pickup Assembly 5 Replace DC Controller PCA Paper light is on steady Ail other lights are off Troubleshooting Printer Error Troubleshooting Table 7 2 Paper Jam Error LaserJet LaserJet 4P 4MP a AL 4ML LEDs Display Panel Description amp Recommendations 13 PAPER JAM 1 Paper in printer Remove paper by referring to Chapter 4 Clearing Paper Jams 2 Rear Door O
162. rts and Diagrams Accessories and Supplies Figure 8 4 Internal Components 1 8 12 Parts and Diagrams Accessories and Supplies Table 8 4 Internal Components 1 PART NO DESCRIPTION RG5 0703 000CN Fan Assembl RG5 0669 000CN Front Oblique Roller Assembl XA9 0654 000CN o Screw M3X10 i 5 1 Formatter PCA C2004 67901 C2004 69001 C2016 67901 C2016 69001 C2006 67901 C2006 69001 C2041 67901 C2041 69001 LaserJet 4L New 1252 5278 1252 5460 LaserJet 4L Exchange LaserJet 4ML New M 7 1 C2003 00032 C2015 00002 C2015 00003 C2005 00013 8 C200340001 E48 3 LaserJet 4MP New LaserJet 4MP Exchange DC Controller Connector LaserJet 4L 4ML LaserJet 4P 4MP RFI Shield LaserJet 4L LaserJet 4ML LaserJet 4ML Mini DIN LaserJet 4P 4MP Switch Acutuator LaserJet 4L ML Screw washer head long 12 mm short 8 mm Power Switch LaserJet 4P 4MP LaserJet 4P Exchange C2005 00004 Font Guide LaserJet 4P 4MP HB1 3405 000CN Grounding Plate LaserJet 4P 4MP RB1 3404 000CN 1 Grounding Plate LaserJet 4P 4MP Part shown in Figure 8 4 is for other printer model actual part looks different Quantity varies dependent on printer model LaserJet 4ML Exchange 0515 2419 0515 2251 LaserJet 4P New RG5 0805 000CN 8 13 Internal Components 2 Figure 8 5 8 14 Parts and Diagrams Accessories and Supplies Table 8 5 inter
163. ry tissue then washing with cold water Hot water causes toner to permanently set into clothing MSDS Information A Material Safety Data Sheet MSDS for toner or any other chemical used in the printer is available through Hewlett Packard s Customer Information Center by either mail or fax By mail To obtain an MSDS for the HP 922744 toner cartridges through the mail call the Customer Information Center CIC at 1 800 752 0900 between 6 A M and 5 P M Pacific Standard Time By fax To obtain an MSDS for the HP 92274A toner cartridges by fax call HP ASAP Automated Support Access Program at 1 800 333 1917 and follow the instructions for using the HP FIRST fax service Note See Technical Assistance later in this chapter for more information on the HP FIRST service Ozone Emission These printers do not use high voltage corona wires in the electrophotographic process and therefore generate no measurable ozone gas O3 The printers instead use charging rollers in the toner cartridge and in the print engine Product Information FCC Statement Class B FCC Statement Class B Note This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to part 15 of the FCC rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and i
164. s and guides inside the printer The pages that print immediately after the jam may pick up this toner Clean spilled toner with a cloth dampened in cold water Do not touch the Transfer Roller with the damp cloth or your fingers Do not use a vacuum cleaner unless it is equipped with a micro fine particle filter Note If toner gets on your clothing use cold water to remove it Hot water sets toner stains into fabric Maintenance Clearing Paper Jams Clearing Paper Jams Note Paper jam messages or status lights will not clear until the printer s Top Door is opened then closed or the front panel button 4L 4ML or T key 4P 4MP is pressed Paper jams can be caused by a variety of factors Leaving the rear door open Filling the paper cassette too full Using paper that does not meet specifications see Media Specifications in Chapter 2 Removing a paper cassette while a job is printing Failing to place the corners of the paper stock under the front and rear retainer clips in the paper cassette Printing a letter size job on legal paper Note Remember to check for loose paper particles and clean any spilled toner after a paper jam has _ been cleared There are three areas of the printer where paper jams can occur The Paper Feed Area Inside the printer Paper Output Area Maintenance Clearing Paper Jams Paper Jams in the Paper Feed Area 1 Open the top door by pressing
165. s reduces the amount of toner used on the page NOTE Software can override this selection even while the EconoMode light is ON OFF EconoMode is off To turn EconoMode on press Keira ATIS to take the printer off line then hold down A iiag while pressing the EconoMode key 3 13 Installation and Configuration Using ihe Control Panel dk ege dH eui uo 13H Jeep sway pepeus ID Sd ALAY Od ud 0334 TWANWW 3j LE 5n KALIA E SHOX NOX pajoojos 31 o2ejed e uaym sieadde Wun top si 3lvu anya MISN3d usan Buaym sieadde un AdOTSANA 1531 3135 1802 9NIOVd SNONS AQY 1N09 OLNY NOIL TI0S3U YIINNN INOS d3dvd ANAN 1S3 mmer Le man aneva Jaen au man gor ANIN 19d 2 nan on 011959 DNO NOX 15808 p uen siedde Au inoswii SeespeopxOd iac WAS WHOS opd app jevomodouc uou gt deier Kgl NOILYLNSINO 1531 4135 0324S HOH NHYM H73 END 398105 1N04 S3ldOO H areMos Yona paBueyo 3q Joues sway nuaw Asay auenyos rou pabueyd eq ued sway nuaw aset LaserJet 42 AMIP Menu Ma 4 gure 3 oe 3 14 Installation and Configuration Service Moda Laserjet AN APAM Service Mode LaserJet 4ML 4P 4MP The Service Mode should be used only by authorized service personnel While in Service Mode you can Print a Service Mode Self Test Verify and set the Page Count the page count also is displayed on the standard self test Set the Cold Reset Default Thi
166. s sets the factory default paper size to either Letter or A4 o Set the Demo Page True False Used to remove the Demo Page option from the self test menu o Set the Diagnostic Functions ON or OFF for software developers use only OO LaserJet 4ML Since the HP LaserJet 4ML does not have a front control panel Service Mode is accessible only through software PJL commands See PJL Software Commands later in this Chapter LaserJet 4P 4MP The following procedure is used to initiate the Service Mode refer to Figure 3 5 1 Hold down the DIE LTH and DS keys while powering ON the printer until all lights are illuminated and the Display Window is blank If the Display Window reads 85 SELF TEST at this point the keys were released too soon Repeat this step until successful 2 Click the RASNI key then the HRI key The message automatitally begins az ILF TES After several seconds both LOEO pu Indicators irn OFF The printer may display 8 is UP ifit has not warmed up completely A the printer Tas warmed up and passed the self test SERVICE is displayed 3 15 Service Mode LaserJet 4ML AP AMP To exit the Service Mode press the key SERVICE MENU races ES Figure 3 5 Service Mode Menu Map LaserJet 4P 4MP only Installation and Configuration Service Mode LaserJet 4ML 4P 4MP Setting the Page Count LaserJet 4P 4MP The page count is stored in the printer s
167. self test can be used to verify installation Page Count Shows how many pages have been printed over the life of the printer Firmware Datecode Shows the datecode of the installed firmware in YYYYMMDD format Installed Options Personalities Lists recognized cartridges and personalities Use to verify installation 10 REt Status Shows the current Resolution Enhancement setting LIGHT MEDIUM DARK or OFF Default is MEDIUM 11 Sample Print Shows ripple print pattern always in Courier This area is useful for checking print density and quality 3 23 Installation and Configuration Printing a Self Test Continuous Self Test A continuous self test can be useful for troubleshooting paper path and other problems To print a continuous self test LaserJet 4L AML 1 Disconnect the printer from the power source Press and hold down the front panel button while connecting power Continue holding the button for 4L about five seconds 4ML about 15 T All lights will illuminate at once then 4L each will light in sequence 4ML all lights stay lit Release the button The printer conducts its internal diagnostics routine then prints the self test page continuously until stopped To stop the continuous self test and reset the printer press and hold the front panel button for a few seconds until all lights begin lighting in sequence once again 4ML the printer can take up to 2 minut
168. set clears all data from the printer s memory and sets all the defaults back to the factory settings NOTE The LaserJet 4L is effectively cold reset whenever power is removed To perform a cold reset LaserJet 4ML Cold Reset can be performed on the LaserJet 4ML through the HP Explorer Utility refer to the Software Solutions package for instructions LaserJet 4P 4MP 1 Turn off the printer 2 While holding the DEZ key down turn the printer on 82 COLD RESET appears briefly on the display then B5 SELF TEST appears 3 After about 30 seconds op OFFLINE appears on the display and the cold reset is complete 4 Press CALA to return the printer on line op REAL appears on the display Installation and Configuration PJL Software Commands PJL Software Commands Many of the control panel functions explained in this chapter can also be accessed through PJL software commands sent from the host computer For the LaserJet 4ML printer functions such as entering Service Mode are accessible only through PJL commands Note that Service Mode is available only on the LaserJet 4ML 4P and 4MP and not on the LaserJet AL The following example shows how to use PJL commands to enter Service Mode and perform various Service Mode configuration tasks Note Text is CASE sensitive in PJL enter exactly as shown The E symbol stands for the ASCII escape character ESC or 027 When the PJL code is entered print the
169. sists of six stages 1 Cleaning 4 Developing 2 Conditioning 5 Transferring 3 Writing 6 Fusing The toner cartridge houses the cleaning conditioning and developing stages of the process Components of the image formation system that wear degrade or are consumed are built into the replaceable cartridge The toner cartridge contains the photosensitive drum primary charging roller developing station toner cavity and cleaning station This eliminates the need for a service call when replacement is required Electrostatic latent image formation block 2 Scanning exposure 4 Flow of paper 4 Direction of drum rotation Developing block Manual feeding slot Figure 5 8 Image Formation Block Diagram 5 22 Functional Overview Image Formation System Photosensitive Drum The photosensitive drum is the heart of the Image Formation System The special properties of this drum allow an image to be formed on the drum s surface and then transferred to paper The drum is an extruded aluminum cylinder The outside of the cylinder is coated with a layer of organic photoconductive material OPC which is non toxic The aluminum base of the photosensitive drum is electrically connected to ground potential see Figure 5 9 Figure 5 9 Photosensitive Drum 5 23 Functional Overview Image Formation System Drum Sensitivity The OPC material has properties similar to a photo resistor It becomes electricall
170. sive Lapel Seecitications D Must not be on any external surfaces of the label before during or after printing Label construction and die cutting must not allow labels to peel off during transport printing or fusing Must not exceed 0 007 in 0 19 mm In ream flat within 0 2 in 5 mm DN Finishing Precision Cut sheet within 0 031 in 0 79 mm of nominal and 0 20 square Fusing Compatibility All adhesives carrier sheets top sheets and other materials used in label construction must be compatible with the heat and pressure of the fusing process Materials must not discolor melt offset or release hazardous emissions when heated to 392 F 200 C for 0 1 second Packaging Moisture proof wrap to preserve properties The flat paper path manual feed slot and rear face up delivery door is recommended for printing adhesive labels 14 Operating Requirements Vedia Soecitications Transparency Specifications Overhead transparencies used in HP LaserJet printers must be able to withstand the 392 F 200 C temperatures encountered in the printer s fusing process for 0 1 second Suitable transparency film is available through Hewlett Packard Refer to Chapter 3 of the HP LaserJet Printer Family Paper Specification Guide HP Part No 5002 1801 for details Caliper 3 9 to 4 3 mils 0 100 to 0 110 mm Cutting Angle 90 0 2 Finishing precision Cut sheet to within 0 03 in 0 8 mm of nominal
171. six times see Figure 2 2 Repeat this action when toner begins to run low Figure 2 2 Distributing Toner e Do not touch the surface of the photosensitive drum in the cartridge Protect the drum from light and contamination e Do not disassemble or refill a toner cartridge e Do not expose the cartridge to unnecessary vibrations or shock e Do not expose the photosensitive drum to strong light White areas on the page may indicate that the drum has been exposed to light for too long If white areas appear stop the printer and wait a few minutes This process should eliminate most defective images If not the toner cartridge may be placed in a dark environment for an extended period of time which may restore some life to the drum e Never manually rotate the drum especially in the reverse direction internal damage and toner spills may result 2 6 Operating Requirements The HP 92274A Toner Cartridge Refilled Toner Cartridges While Hewlett Packard does not prohibit the use of refilled toner cartridges during the warranty period or while under a maintenance contract we do not recommend their use The reasons for this are e Hewlett Packard has no control or process to ensure that a refilled toner cartridge functions at the high level of reliability of a new HP LaserJet toner cartridge Hewlett Packard also cannot predict what the long term reliability effect on the printer is from using different toner formulations found
172. st lasers teen p syn laitteen ulkopuolelle Kirjoittimen on hyv ksynyt Suomessa laserturvallisuuden osalta S hk tarkastuskeskus Laitteen turvallisuusluokka on m ritetty valtioneuvoston p t ksen N o 472 1985 ja standardin EN 60825 1991 mukaisesti VAROITUS Laitteen k ytt minen muulla kuin k ytt ohjeessa mainitulla tavalla saattaa altistaa k ytt j n turvallisuusluokan 1 ylitt v lle n kym tt m lle lasers teilylle VARNING Om apparaten anv nds p annat s tt n i bruksanvisning specificerats kan anv ndaren uts ttas f r osynlig laserstr lning som verskrider gr nsen f r laserklass 1 HUOLTO HP LaserJet s 4L 4ML 4P amp 4MP kirjoittimen sis ll ei ole k ytt j n huollettavissa olevia kohteita Laitteen saa avata ja huoltaa ainoastaan sen huoltamiseen koulutettu henkil T llaiseksi huoltotoimenpiteeksi ei katsota v riainekasetin vaihtamista paperiradan puhdistusta tai muita k ytt j n k sikirjassa lueteltuja k ytt j n teht v ksi tarkoitettuja yll pitotoimia jotka voidaan suorittaa ilman erikoisty kaluja VARO Mik li kirjoittimen suojakotelo avataan olet alttiina n kym tt m lle lasers teilylle laitteen ollessa toiminnassa l katso s teeseen VARNING Om laserprinterns skyddsh lje ppnas d apparaten r i funktion uts ttas anv ndaren f r osynlig laserstr lning Betrakta ej str len Tiedot laitteessa k ytett v n laserdiodin s teilyominaisuuksista
173. t including toner cartridge Humidity 15 90 no condensation Acoustic Emissions 4L 4P 4ML 4MP Operation position per ISO 9296 DIN 45635 T 19 Printing Lpa dB A Standby Lpa dB A Bystander 1m per ISO 7779 DIN 45635 T 19 Printing LPAdB A Standby Lpa dB A Sound Power per ISO 9296 Printing LPA dB A 1 5 Product Information Product Overview Product Overview External Assembly Locations LaserJet 4L 4ML Front of Printer Front Panel Button Status LEDs Top Paper Output Tray Face Down Manual Feed Slot Paper Cassette Toner Cartridge Top Door Release Button Back of Printer Power Door Rear Access Door Face Up Delivery Slot Paper Path Knob O Door Paper Release Lever Fuser Area Memory Door Product Information Product Overview External Assembly Locations LaserJet 4P AMP Front of Printer Top Paper Output Tray Face Down Control Panel Keys Top Door Release Button Power Switch Mechanical Paper low Indicator Toner Cartridge qo e Fan 16 Character Display Manual Feed Slot Paper Cassette Back of Printer occured Power Input Rear Access Door Face Up Delivery Slot i d Access Panel Paper Path Knob VO Panel Paper Release Lever Output Rollers Fuser Area Face Down Output Defectors Figure 1 3 External Assembly Locations LaserJet 4P 4MIP 1 7 Product Information Product Overview Internal Asse
174. t out Figure 6 47 3 Lift the Toner Cartridge Lever Assembly out to remove moving the Toner Cartridge Lever Assembly Figure 6 47 Re 6 52 Removal and Replacement Boitom Assemblies Top Door Switch Plunger Assembly Remove the Printer Cover the Fusing Assembly Figure 6 27 the Formatter Shield and PCA Figure 6 13 the Power Switch Assembly LaserJet 4P 4MP only Figure 6 23 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 2 Pry outward on the tab and slide the Top Door Switch out of the printer Figure 6 48 Figure 6 48 Removing the Top Cover Switch Plunger Assembly 6 53 Switch Arsenius Ee 4P 4MP MUR Und 6 23 Remove the Laser Scanner Assembly Figure 6 21 the Gear Train Assembly Figure 6 15 the DC Controller Assembly Figure 6 36 and the Feeder Guide Assembly Figure 6 44 From the left side of the printer release pressure on the two tabs Figure 6 49 callout 1 OF PRIN Figure 6 49 wmm ihe Side Tabs DC Controller Scanner Connector continued on next page Removal and Replacement Bottom Assemblies 4 From the top of the printer lift the connector assembly out Figure 6 50 callout 1 H t c r o Figure 6 50 The DC Controllez Scanner Connector Location 6 55 Removal and Replacement Bottom Assemblies PS1 Input Paper Sensor Arm The PS1 Input Paper Sensor Arm is located under the Feeder Guide Assembly an
175. ted under the left and right ends of the Transfer Roller refer to Figure 6 25 It is not necessary to remove the Printer Cover to replace the bushings 1 Open the top door and remove the toner cartridge 2 Remove the Transfer Roller Figure 6 25 3 Remove the 1 self tapping screw and lift the bushing straight out the same procedure applies for both the left and right bushings 6 98 Removal and Replacement internal Assemblies Beam to Drum Mirror Assembly Note Be careful not to touch the surface of the mirror on the underside of the assembly If the mirror does get contaminated use filtered compressed air to clean If still dirty clean it carefully using lens cleaner and a lint free cloth or swab 1 Remove the Printer Cover 2 Note where the mark on the printer chassis aligns with the graduated scale on the mirror Figure 6 26 callout 1 3 Remove the 2 self tapping screws Figure 6 26 callout 2 Grasp the mirror assembly by the sides only and lift to remove Adjustment Scale b ue a SCH vend dic MIR Figure 6 26 Removing the Beam to Drum Mirror To re install Install in the correct alignment as noted in step 2 Check adjustment according to the Beam to Drum Mirror Adjustment procedure in Chapter 7 6 29 Removal and Replacement Rear Assemblies Rear Assemblies Fusing Assembly 1 Remove the Printer Cover 2 Remove the machine screws with star washers 1 on 4L 4ML
176. tement Finland 1 12 Declaration of Conformity 1 13 Toner Safety 1 14 MSDS Information 1 14 By mail 1 14 By fax 1 14 Ozone Emission 1 14 FCC Statement Class B 1 15 VCCI Statement Japan 1 16 Service Approach 1 17 Exchange Program 1 17 Ordering Parts 1 17 Ordering Consumables 1 17 Ordering Related Documentation 1 18 Print Utilities 1 19 Technical Assistance 1 20 HP ASAP 1 800 333 1917 U S 1 20 HP FIRST 1 20 HP FIRST U S 1 20 HP FIRST Europe 1 20 HP AUDIO TIPS 1 21 HP CompuServe Forum 1 21 Customer Information Centers 1 21 Customer Support Center Assist Line 1 21 European Customer Support Center 1 22 Other Areas 1 22 Chapter 1 Contents Page 1 2 Operating Requirements Site Requirements 2 2 Operating Environment 2 2 Printer Space Requirements 2 3 The HP 92274A Toner Cartridge 2 4 Storage Conditions 2 4 Storing Opened Toner Cartridges 2 5 Toner Cartridge Handling Suggestions 2 6 Refilled Toner Cartridges 2 7 Recycling Toner Cartridges 2 7 Media Specifications 2 8 Media Sizes Supported 2 9 Media Selection Guidelines 2 10 Envelope Specifications 2 12 Adhesive Label Specifications 2 13 Transparency Specifications 2 15 Storing Print Media 2 16 Shipping Print Media 2 16 Chapter 2 i Contents Page 1 Chapter Contents amp Installa
177. tenance Clearing Paper Jams 3 If the paper is difficult to remove you need to relieve some of the pressure in the Fusing Assembly Open the printer s rear access door While holding the green paper release lever up pull the paper out Figure 4 6 Releasing Paper from the Fusing Assembly 4 Replace the paper cassette and the toner cartridge then close the top and rear doors The printer should return to the Ready state If it does not try one of the following remedies Ensure the rear access door is fully closed and latched Check to see if there is more jammed paper in the printer see the next page Open and close the printer s top door or press the front panel button briefly 4 11 Maintenance Clearing Paper Jams Paper Jams in the Paper Output Area L Open the printer s Top Door and remove the toner cartridge 2 Open the rear access door CAUTION Do not touch the fusing assembly It may be hot 3 While pushing the green paper release lever up pull the paper out This lever releases pressure on the fuser roller Figure 4 7 Clearing Jams from the Fuser Area 4 Be sure to close the rear access door again Leaving the rear access door open will cause a paper jam Note If there is still a paper jam error condition check the paper feed and top door areas for paper or particles Ifthe error persists refer to Chapter 7 Troubleshooting H PRINT apporox 10 4 to 10 8 8 4
178. the print engine within a specified amount of time after the Input Paper Sensor PS1 reaches the Top Position The leading edge is now aligned ready to proceed under the photosensitive drum After the paper passes under the drum past the Winding Sensor PS4 and through the fusing unit it triggers the Exit Paper Sensor PS3 The paper is then fed through either the face up delivery slot or the face down output rollers and to the top output tray depending on the position of the face up deflectors 5 37 Functional Overview Paper Feed System Manual Feed Printing The presence of paper in the manual feed slot is detected when the Input Paper Sensor PS1 reaches the Manual Feed Sense Position The Manual feed system s paper motion begins when the DC Controller PCA after receiving a PRINT signal starts the Scanner Motor the Main Motor and the fuser heating element The Registration Solenoid SL1 is OFF at this time allowing the registration roller to rotate This feeds the paper from the Manual Feed slot to the Registration Position The remainder of the manual feed print process is identical to the cassette feed process described above Small Media Rollers LaserJet 4P 4MP The LaserJet 4P AMP bas an additional set of Small Media Rollers located midway between the pickup and delivery rollers see Figure 5 18 These rollers allow the printer to accept a smaller minimum paper size 3 x 5 inches 76 x 127 mm E Oo Function
179. tion and Configuration Unpacking and Installation 3 2 A Choose the best location 3 2 B Unpack the printer 3 2 C Check package contents 3 3 D Install the toner cartridge 3 3 E Load the paper cassette 3 4 F Attach the interface cable s 3 4 G Attach the power cord 3 5 H Attach the Help Labels Lase Jet 4L 4ML only 3 6 I Install Printer Drivers and Utilities optional 3 7 How to Obtain Printer Drivers 3 7 Using the Printing Software Package 3 8 Using the Control Panel 3 9 LaserJet 4L AML Control Panel Overview 3 9 The LaserJet 4L AML Lights 3 10 The LaserJet 4L 4ML Front Panel Button 3 11 LaserJet 4P 4MP Control Panel Overview 3 12 LaserJet 4P 4MP Control Panel Display and Lights 3 13 Service Mode LaserJet 4ML 4P 4MP 3 15 LaserJet 4ML 3 15 LaserJet 4P AMP 3 15 Setting the Page Count LaserJet 4P AMP 3 17 Setting the Cold Reset Default LaserJet 4P AMP 3 18 Other Service Mode Items 3 18 Printing a Self Test 3 19 LaserJet 4L 4ML 3 19 LaserJet 4P AMP 3 19 The LaserJet 4L Self Test Fields 3 21 The LaserJet 4ML 4P 4MP Self Test Fields 3 23 Continuous Self Test 3 24 LaserJet 4L 4ML 3 24 LaserJet 4P 4MP 3 24 Engine Test 3 25 continued on back Chapter 3 Contents Page 1 Resetting the Printer 3 26 LaserJet 4L 4ML 3 26 LaserJet 4P 4MP 3 26 Simple Res
180. to zero whenever the printer is powered off 10 Firmware Datecode Shows the datecode of installed firmware in YYYYMMDD format 11 Image Adapt Status Displays YES if the Image Adapt data compression feature has been invoked since the last power on 12 Control Errors Shows the number of I O or misprint errors since the last power on 3 21 Installation and Configuration Printing a Seif Tesi KP LaserJet 4MP Printer 7 PCL Config Page mensen ANERE SERVICE MENU PRINTING MENU PCL MEKU H PAGES 420 COPIES 21 FONT SOURCE 1 Internal CR PAPER LETTER PAPER LETTER FONT NUMBER 0 SKIP DEMO FALSE ORIENTATION P Portrait PITCH 10 00 DIAGNOSTICS OFF FORM 60 LINES SYM SET ROMAN 3 MANUAL FEED OFF RET MEDIUM PS MENU OB MENU CONFIG MENU PRT 9S ERRS ON PAGEPROTECT AUTO CLR WARN ON RESOLUTION 600 AUTO CONT QN PERSONALTY AUTO DENSITY 23 TIMEOUT 300 PARALLEL MENU SERIAL MERU TEST MENU HIGH SPEED YES SERIAL Rs 232 SELF TEST ADV FHCTNS ON PACING DTR OSR CONT SELF TEST BAUD RATE 9600 PCL TYPE LIST DYR POLARITY MI PCL DER PAGE PS CONFIG PAGE PS TYPEFACE LIST PS DEMO PAGE SE Cer MEDIUM Z DES Local Talk Mame LaserJet ANE Localfalk Mode ED 254 R EconoMode OFF formatter Number SO4601027KG RAM size 6144K bytes Page Count 420 P Firmware Datecode 19930121 Installed Options NONE Installed Personalities f PCL
181. tor LJ 4L ML C2003 40001 Switch Cam Assembl RG5 0672 000CN 8 6 ala Top Oblique Roller Assembly RGs0670 000CN Lag Universal Paper Cassette LJ 4L AML R7 amp 0010 000CN 89 XD2 2300 402CN a3 c 8 2 Darta Tada Q Parts Index Numerical Paris Index Numerical Parts Index PART NUMBER DESCRIPTION 0515 2251 Screw washer head short 8 mm 0515 2419 Screw washer head long 12 mm 1252 5278 DC Controller Connector LJ 4L 4ML 1252 5460 DC Controller Connector LJ 4P AMP C2003 00005 Nameplate LJ 4L C2003 00032 RFI Shield LJ 4L Switch Acutuator LJ 4L ML Fuser Assembly 100 120V Exchange DC Controller PCA 100 120V LJ 4L 4ML Exchange DC Controller PCA 220 240V LJ 4L 4ML Exchange C2003 69005 Laser Scanner Assembly LJ 4L 4ML Exchange Formatter PCA LJ 4L New Formatter PCA LJ 4L Exchange C2005 00001 Nameplate LJ 4P C2005 00004 Font Guide LJ 4P 4MP RFI Shield LJ 4P 4MP VO Cover Plate LJ 4P Keyboard Overlay Euro English Keyboard Overlay Turkish Keyboard Overlay Portuguese Keyboard Overlay German Keyboard Overlay Spanish Keyboard Overlay French Keyboard Overlay Italian C2005 40009 Keyboard Overlay Dutch C2005 40010 Keyboard Overlay Norwegian 8 13 Parts Index 9 Parts Index Numerical Parts Index PART NUMBER DESCRIPTION C2005 4001 1 Keyboard Overlay Polish K co oo 8 13 8
182. ur Try a different paper lot see Media face of the paper may be too coarse Specifications in Chapter 2 causing repeated marks 7 29 Troubleshooting Image Formation Troubleshooting Table 7 25 Staining POSSIBLE CAUSE RECOMMENDED ACTION 1 Printing on wrong side of paper The Check for the arrow on the paper label on the ream of paper indicates wrapper Be sure paper is loaded with which side to print on The different sur the arrow pointing down in the paper face properties of some papers may cassette cause problems if loaded wrong side up 2 Dirty printer Clean the inside of the printer as described in Chapter 4 3 Dirty Transfer Roller This problem is Clean the Transfer Roller using a dry characterized by staining on the back of lint free cloth the paper and will not occur unless the Transfer Roller is extremely dirty 4 Toner build up in the Fusing Assem Remove and clean the Fusing Assembly bly Toner build up can physically dam see Chapter 6 age the Fusing Assembly 5 Toner build up caused by duplexing Either avoid duplexing or clean the printer more often 6 Leaking toner cartridge Replace the toner cartridge 7 Paper does not meet specs The pa Try a different paper lot see Media per moisture content conductivity or sur Specifications in Chapter 2 face finish may not work correctly with the printer s electrophotographic 77 20 Troubleshooting
183. utput Assembl Co fo R Roller Upper Output Assembl Gear Train Plate Assembly LJ 4L 4ML Cover Assembly LJ 4L 4ML Door Back Assembly LJ 4P 4MP Switch Plunger Assemb High Voltage Connector Assembl V l l oo ro p ro oo o fan CO oO co oco N O1 9 7 Parts Index 13 Parts Index Numerical Parts Index RQ5 0703 000CN Iran Assembi canner Connector Assembl S RG5 0767 000CN DC Controller PCA 220 240V LJ 4L 4ML New G RG5 0791 000CN ear Train Plate Assembly LJ 4P 4MP Co co o ao IN LE CO Cc CO Co co jN RG5 0793 000CN Juge Feeder Assembly LJ 4P 4MP RG5 0794 000CN Roller Assy Small Media LJ 4P 4MP Pickup Assembl eam to Drum Mirror Assembly LJ 4P AMP ower Switch over Assembly LJ 4P AMP Control Panel PCA LJ 4P 4MP D D CO 11 P oo co Joo l l l l l FS Il d co lo lo do do AK ch D B CH C Controller PCA 100 120V LJ 4P AMP New C Controller PCA 220 240V LJ 4P AMP New Paper Feed Solenoid SL1 l Spring Top Door Compression LJ 4L 4ML Spring Top Door Compression LJ 4P 4MP S S CO Po RS5 2228 000CN pring Top Door Latch LJ 4L 4ML RS5 2228 000CN pring Top Door Latch LJ 4P 4MP RS5 2229 000CN Spring Compression Small CO o oo w Po joo Parts Index 14 Paris Index Numerical Parts Index Cw xnexa mr Spring C
184. ved from the Formatter the DC Controller sends a signal to the Laser Scanner PCA to modulate the laser diode ON and OFF The modulated laser beam strikes the surface of a rotating scanning mirror is directed through a focusing lens onto the Beam to Drum Mirror and is then reflected onto the photosensitive drum Synchronization of the process is achieved by continuous monitoring of the beam detect signal which is fed back to the system from one end of the focusing lens Refer to Image Formation System later in this chapter for more information Paper Motion Monitoring and Control The DC Controller PCA controls paper motion by continuously monitoring the various paper sensors and coordinating the timing with the other print processes For a detailed explanation of paper movement and the interaction of photosensors and solenoids with the paper movement process refer to the section Paper Feed System later in this chapter 5 5 Functional Overview DC Controller Power System Top Door Toner Cartridge Microswitch SW201 Microswitch SW201 located on the DC Controller is activated by both the top door and the toner cartridge If either the top door is open or the toner cartridge is not installed the switch opens and an error is issued by the Formatter On the LaserJet 4L 4ML the front panel s Error topmost LED turns on steady On the LaserJet 4P 4MP the display panel message 17 OPEN GF HO EF is displayed A toner cartrid
185. ware toner by reducing the dot density This through HP Explorers Remote Control may appear to be a print quality problem Panel or through the front control panel in some cases LaserJet 4P AMP 4 Paper does not meet specs The mois Try a different paper lot see Media ture content conductivity or surface fin Specifications in Chapter 2 ish may not work correctly with the printer s electrophotographic process 5 Transfer Roller is defective or incor Inspect the Transfer Roller for proper rectly installed If the transfer roller loses installation and contact If the Transfer conductivity it cannot effectively pull Roller is damaged replace it toner from the drum to the 6 Laser Scanner door not opening properly 1 Remove and re seat the toner cartridge 2 Check the Laser Scanner shutter door for proper operation If defective replace the Laser Scanner Assembly Check the pins and springs for 7 High Voltage Connector Assembly is defective The High Voltage Connector _ functionality If dirty clean using alcohol Assembly mounts on the DC Controller if damaged replace the High Voltage PCA and uses spring loaded pins to con Connector Assembly tact the toner cartridge 8 DC Controller PCA is defective The Replace the DC Controller PCA DC Controller supplies the proper volt age to the High Voltage contacts 77 OF
186. with the cable hole and close the I O Door 3 Attach the I O cable to the computer RA Installation and Configuration Unpacking and Installation G Attach the power cord 1 LaserJet 4L 4ML Open the Power Door at the right rear of the printer by pressing on the back end of the door and swinging it outward Connect the power cord On the LaserJet 4P 4MP turn on the power switch on the right side of the printer All front panel lights briefly illuminate then the green Ready light comes on LaserJet 4P 4MP There is a brief self test period before the cid and the On Line lights are illuminated and the display reads amp Mp LaserJet 4L 4ML Align the power cord with the hole at the rear of the door and close the Power Door LaserJet 4L 4ML Briefly press the front panel button to generate a self test and verify that the printer is working LaserJet 4P 4MP Press the T1573 key then Menu ee until ee i appears Then press REIA once to display SELF TEST Prees lente to print a self test oie Refer to the section Printing a Self Test later in this chapter for a detailed description of self test information Power On Off The LaserJet 4P 4MP uses a conventional on off power switch The LaserJet 4L and 4ML printers do not have a power switch but use Intelligent On Off sensing instead See Intelligent On Off in Chapter 5 o D 3 5 and the small Figure 3 1 Bo
187. y Door 6 6 memory enhancement technology MEt theory 5 19 memory error control panel message 3 10 memory management theory 5 19 memory upgrade 6 4 when needed 3 10 memory standard amp optional 1 2 memory language SIMMs 6 5 menu of resets 3 27 monthly usage 1 2 motors theory 5 7 MSDS 1 14 N non volatile memory NVRAM theory 5 14 NVRAM error 68 ERROR 7 12 NVRAM Reset 7 17 Index 3 UE SOCAL CTU4ES T Ak parallel eable bi tronics B 2 parallel interface theory 5 14 parts ordering 1 17 8 2 Parts Center Europe PCE 1 17 8 2 Parts Direct Ordering PDO 1 17 8 2 parts index listing by name A 2 A 8 listing by part number A 9 A 16 printer drivers 3 7 printer drivers obtaining 3 7 printer error troubleshooting 7 6 7 18 printer featureslist 3 21 printer languages 1 2 printer lights functions 3 10 printer space requirements 2 3 printing a self test 3 19 3 24 printing engine test LJet 4L 4ML 7 36 Index printing engine test LJet 4P 4MP 7 37 removal and replacement 6 1 priority of errors 7 7 processing data control panel message 3 10 product information 1 1 1 22 product overview 1 6 1 10 PS1 theory 5 36 PS2 theory 5 35 R radio frequency interference RFI 1 15 RAM ROM error 53 ERROR 7 14 RAM size 3 21 random access memory RAM theory 5 13 read only memory ROM theory 5 13 Ready light 3 10 rear assemblies 6 30 6 38 Rear Door 6 12 re
188. y conductive when exposed to light When the photosensitive drum is exposed to light the negative charges deposited on it are conducted to the ground potential of the drum s base Areas not exposed to light remain nonconductive and maintain their negative charge CAUTION The printer s toner cartridge does not include a light blocking shutter Be careful to avoid exposing the drum to light which can permanently damage the drum Protect the cartridge whenever removing it from the printer preferably by inserting it into the protective bag _ from its packaging Time t 9 T uns a gt v o D St t2 20 oe Primary Scanning Transfer Primary charging exposure charging Figure 5 10 Drum Surface Potential 5 24 Functional Overview Image Formation System Cleaning Stage During the cleaning stage of the image formation process the drum s surface is physically cleaned preparing it to hold an image During printing the drum is rotating constantly making several complete rotations per printed page Before forming the image for a given section of print a cleaning blade removes toner from the previous rotation of the drum The excess toner is stored in the toner cartridge where it is prevented from being used in later print jobs see Figure 5 11 Cleaner container Cleaning blade Photosensitive drum Sweeper strip Figure 5 11 Drum Cleaning 5 25 Functional Overview Image Formation System Conditio

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