JANUARY 1985 TROUBLESHOOTING 3
Contents
1. THE MONITOR CONTAINS HIGH VOLTAGE CIRCUITRY DISCHARGE THE ANODE IM MEDIATELY AFTER THE CASE IS REMOVED USE CAUTION IF POWER IS APPLIED DURING TESTING AND USE NON CONDUCTIVE ADJUSTMENT TOOLS WHEN WORK ING ON THE MONITOR Inspect the interior of the monitor for burned or damaged components or loose connections Re pair or replace malfunctioning components and retest Is the monitor functional YES Go to step 7 NO Check the SUB BRIGHT adjustment R37 it adjustment does not produce a clear display go to step 5 STEP 5 Test the monitor power supply on the 12V line Is the voltage 10 8 13 2V YES Check the heater of the CRT and the voltage at pin 2 of the FBT If the heater is not lit or the voltage is not approximately 485V replace the flyback transformer Section 4 5 5 and retest If the FBT is operative but the monitor remains malfunctional go to step 6 NO Replace the monitor power supply and retest if the malfunction is not corrected go to step 6 STEP 6 Check the CRT G1 and G2 voltages is Gi approximately 21V to 44V and G2 approximately 485V YES Exchange the monitor unit if malfunctionat at this step NO Replace the monitor main circuit board Section 4 5 7 and retest if the malfunction is not cor rected at this step exchange the monitor unit 33 TROUBLESHOOTING M TM OX16 STEP 7 YES NO STEP 8 YES NO STEP 9 YES NO STEP 10 YES NO 3 4 JANUARY 1985 Install2. CPUs 2764s IPL or BIOS 74t 154 t O selectors OD controrier GAAFDC SED9421COB VFO 8237 DMA controti ers 8255 printer i lers 8253 ce TALSTSA 7201C seral ntertace 8259 interrupt co timecicounter 8C 8255 p VO solector terface 8259 interrupt ler 8D 8255 print 146818 real timo clock 8259 interrupt controllers 8259 nterrupt contraliers 8237 DMA controllers 201C seriai interlace 8258 interrupt controllers 8253 imer counter 9C 74LS154 1 0 selector APX GGS 7201 graphic display controller GAAPGD 8284A character generator APX ICRT 6845 CRT controller character generator
3. BIOS EPROM Y141800102 2764 IPL EPROM Y141810102 50256 256K DRA X400502560 8237 DMA Controller X400082370 8259 Interrupt Controtier 400082590 8253 Counter Timer X400082530 7201 Graphic Disptiy Ceetroler X400072010 8255 Programmable Peripheral In 400082550 146818 Rea Time Crock 400014630 449 CMOS RAM X400004491 765 FDD Controller X40000765 1 APX IGGS Video Board unit Y142202000 7220 Graphic Display Controller X400072204 GAAPGO Y140800000 41254 64K x 4 DRAMs X400412541 APX ICRT Video Emulaton Board Unit Y 143201000 46505 CTRC X400065050 2764 Character Generator X630112830 Monitor Unit Q602A Monitor Main Circu Board Y138501213 CRT Y139501007 50 543 FDO Unit 141501000 Main Crout Board 295250401 Keyboard Umm O603A AA Keyboard Upper Case 2 Y142501001 Keyboard Cover Case Y142501002 Keyboard Circuit Board 142801044 TABLE 3 2 MODULAR TROUBLESHOOTING TOOLS TOOL PART NUMBER Phillips screwdriver 1 8743800100 Digital VM Syslern disk CP M and MS DOS Blank disk 96 tj TROUBLESHOOTING M TM QX16 JANUARY 1985 STEP 1 Connect the main unit to AC mcnitor and keyboard disconnected and turn the power on Do the YES NO STEP 2 3 2 YES NO STEP 3 YES NO main unit power LED and FDD arive select LEDs tight and does the fan operate Go to step 3 Make sure the AC cable is securely connected and retest if the problem is not corrected remove the upper case from th
4. X ICRT or exchange the 7201C on the APX ISYM board or replace the APX ISYM board If the monitor does not operate at all with the second CPU unit exchange the monitor or further troubleshoot it by referring to step 4 If the monitor operates but the vertical or horizontal adjustment cannot be corrected replace the monitor main circuit board or exchange the monitor If the TESTING RAM display message appears followed by an error code referto Table 3 3 and perform the appropriate IC exchange TROUBLESHOOTING TABLE 3 3 IPL CODES MESSAGE REMEDY IPL VERSION 1 XX TESTING RAM Normal operabon INSERT SYSTEM DISKETTE iN LEFT DRIVE RAM ERROR PRESS RESET TO RETRY Repiace suspect socketted RAMs or replace the APX ISYM board then retry Z80 PROCESSOR CHIP FAILED Replace the Z 80A CPU Replace the PRESS RESET TO RETRY APXASYM board if necessary 16 BIT CARD NOT INSTALLED Replace the system control latch 748154 and UNABLE TO BOOT SYSTEM retry Replace the APX ISYM board if necessary INVALID SYSTEM TRACKS FOUND Replace the disk and retry HARD DISK NOT RESPONDING ERROR READING HARD DISK PRESS RESET TO RETFY Probable hard disk damage Refer to the oper ERROR READING THE HARD DISK ation and technical manuals tor the hard disk PARTITION TABLE INVALID PARTITION TABLE FOUND STEP 4 To troubleshoot the monitor begin by removing the monitor upper case and discharging the CRT anode Section 4 5 1 DANGER
5. d Section 4 2 9 When the system is operative proceed to step 9 With the system disk booted al FDD A and a blank disk inserted in FDD B attempt to format the blank disk and write and read data to and from each drive Is the data recorded and retrieved accurately and is the time display accurate Go to step 10 If the time drifts or is incorrect replace the NiCd battery and recheck If formatting or data read write fails exchange the 765 13A on the APX ISYM board and retest If swapping the ICs does not remedy the malfunction replace the APX ISYM board From the operating system type CTRL G Does the speaker sound Repeat the modular test sequence the unit should now be completely functional If an optional peripheral fails to operate with the QX 16 test the device in a known operative computer if the option operates with the second CPU unit replace Ihe 8255 or the APX ISYM board Replace the 8253s 9C and 10Ci on the APX ISYM board one at a time retesting after each swap then repeat the modular test sequence the unit should now be functional MIMQXIE TROUBLESHOOTING TABLE 3 4 PLUG IN IC TROUBLESHOOTING REFERENCE GUIDE SYMPTOM PROBABLE CAUSE Goes not boot FDD does not readiwnte RS 232C does not operat No printout Calendar does not update Option card doe Keyboard does not in Display matfunchons 0t opera 8237 DMA controller 256K DRAMs Z 804 or 8088
6. e main unit Section 4 2 1 and check fuse F1 on the Q10PS board Replace the fuse if damaged and retest If the fuse blows or the unit remains malfunctional go to step 2 Measure the supply voltage at CN11 on the APX ISYM board is 4 5V present at pin 7 12V at pins 2 3 and 4 and 12V at pin 5 If the voltage is correct but the fan or LEDs are inoperative replace the malfunctioning item When the main unit is operative go to step 3 Replace the Q10PS board Section 4 2 3 Connect the monitor to the CPU unit and to AC and power both Does the monitor LED light and does the following display appear IPL VERSION X X TESTING RAM And does the second line of the display change to the following INSERT SYSTEM DISK IN LEFT DRIVE Go to step 7 If there is no display check the brightness and contrast controls then check all cable connections and retest If necessary test the monitor with another CPU unit to verify whether the malfunction lies in the monitor or the CPU If the monitor operates with the second CPU unit inspect the APX IGGS and APX ICRT circuit boards for poorly seated or damaged components cracks lifted traces or misplaced or loose connectors Replace any board showing obvious damage If the boards appear undamaged ex change the following ICs one at a time retesting after each swap APX GGS 7220 APXICRT 46505 GAAPGD 2764 2764 If the malfunction is not eliminated by chip exchange replace the APX IGGS or AP
7. i MEIMONG JANUARY 7985 TROUBLESHOOTING 3 CHAPTER TABLE OF CONTENTS Section Tie Page 34 MODULAR TROUBLESHOOTING lt ocsi isusu itise c cece ns 34 LIST OF TABLES Table Tite Page 34 Modular Subassemblies HeRindibifuieqs ea nie see tiet 35 sio ote 34 3 2 Modular Troubleshooting Tools A a 3 IPLCodes isos iiis inea eraan eds 3 3 3 4 Plug In iC Troubleshooting Reference Guide 3 5 ATMQXIS TROUBLESHOOTING JANUARY 1985 3 1 MODULAR TROUBLESHOOTING Modular troubleshooting enables isolation of malfunction to the items listed in Table 3 1 and is accomplished using the following test sequence which verifies the operation of the main CPU unit monitor keyboard and FDODs Table 3 2 lists tools necessary for modular testing Table 3 3 lists the IPL error codes and Table 3 4 is a troubleshooting reference guide for determining malfunctioning ICs according to malfunction symptom NOTE Units received from the field should be carefully inspected for signs of misuse or shipping damage Note the packing materisls used to ship the system if applicable and look for protective spacers between the read write heads and for the shipping support at the option port TABLE 3 1 MODULAR SUBASSEMBLIES REPLACEMENT MODULE COMPONENT PART NUMBER Q 0PS Power Supply Board Y130203000 Fan Unit Y130501000 APX ISYM Control Boara Unit without ROMs Y141201000 Z 80A CPU X400007801 8088 2 CPU X400080881 2764
8. the keyboard Do the LEDs on the SHIFT ALPHA and INSERT keys blink then turn off and does the character generated by each key correspond with the symbol on the keytop Go to step 8 Check the keyboard with another QX system if possible to verify whether the malfunction fies in the keyboard or the main CPU unit If the keyboard is operable wher connected to the second QX exchange APX ISYM board ICs in the following order retesting after each swap 7201 18 8253 9C 8259 9D If the malfunction is not corrected or the keyboard is not functiona with a known operative ma chine check the socket contact of the keyboard CPU If necessary repiace the keyboard circuit board Section 4 4 3 or the keyboard Insert a system disk in the left orive and press the disk insertion button Does the system boot Go to step 9 Recheck the unit using another system disk if the system boots the backup go to step 9 If the system does not boot remove the the FDD connectors from the APX ISYM board and install the drive B connector at CN6 Retest the booting operation by inserting the system disk in the B right drive If the system boots on FDD B replace FDD A and reconnect the connectors in their original orientation FDO A to CN6 FDD B to CN7 and retest If the system still does not boot exchange the 765 13A on the APX ISYM board and retest If the malfunction is still not correctec replace the FDD Section 4 3 1 or the APX ISYM boar
Download Pdf Manuals
Related Search