Service Manual Versions and Revision
Contents
1. 3 5 System reset LED control circuit 3 6 EPROM mm 4 7 Controller circuit 4 7 1 Dection of POWER switch status 4 7 2 Display mode identification 4 7 3 User control 6 7 4 Control of identification converter LSI 7 7 5 PC bus control 7 7 6 Power ON sequence 8 7 7 Power OFF sequence 9 7 8 List of CPU assignments 10 8 Power Board Operation Therory 11 9 Inverter Cir2. Service Manual 17 inch LCD Monitor f1723 FP7317 L1702 vf17 FP17 Service Manual Versions and Revision Version Release Date Revision Feb 20 2003 Original release April 8 2003 Update Copyright Trademarks Copyright 2003 LiteOn Technology Corp LiteOn is a registered trademark of LiteOn Technology Corp All Rights Reserved All other trademarks are the property of their i al may not in whole or in part i This manu y not in whole or in part be copied respective owners photocopied reproduced translated or converted to any electronic or machine readable form without prior written permission of LiteOn Technology Corp f1723 FP7317 L1702 vf17 FP17 Service Manual LA f1723 FP7317 L1702 vf17 FP17 1 Circuit Description 1 Audio circuit 3 1 1 Audio input 3 1 2 Audio output 1 3 2 Power supply 3 3 Video input circuit 3 4 Definition converter LSI peripheral circuit
3. y Check the output of 3 3V line voltage from 1301 pin 4 NG Failure point um 1301 failure y Failure point Printed wire broke between 1301 pin 4 and IC 304 power supply pin Page 22 LA f1723 FP7317 L1702 vf17 FP17 10 Power Board Check output voltage 22 5V 12V is right or not Y No gt It is not power board problem AA Check power switch is turn on or not No gt Yes Turn switch on y Check power cord P801 signal cable P302 P802 P803 CN102 CN103 is connected right or not No gt Connect it right Yes AA Check C805 is about DC140V 330V or not No gt Check F801 pice P801 and repair Yes them Vv Check C807 is over 10V or not Check R805 R803 1801 and repair No gt Yes them v Check pin 6 of 1801 have same pulse or not Check peripheral co of 1801 and No gt repair them Yes v Check pin 1 of T802 have same pulse or not No P Check Q803 R813 R814 D806 Yes R812 and repair them y Check peak voltage of R811 triangle pulse is up to 1 volt or not No gt Check D804 R807 and repair them Yes v Check D809 D810 C816 C821 T802 have same short circuit or the output 22 5V 12 5V is over lo
4. Module ON OFF control is performed for power ON OFF and also for the power saving sequence 3 Video input circuit Circuit diagram MAIN PWB 3 5 The analog video signal input entered from P302 the AC coupled video signal is used to clamp the black level at OV 4 Definition converter LSI peripheral circuit Circuit diagram MAIN PWB 4 5 1304 gm2121 is the definition converter LSI The analog R G B signal input entered from the video input circuit is converted into the digital data of video signal through the incorporated A D converter Based on this conversion this device performs interpolation during pixel extension The source voltage for this device is 3 3V 2 5V and the system clock frequency is 14 318 MHz The withstand voltage level for the input signal voltage of 1304 is 3 3V and SV 5 System reset LED control circuit Circuit diagram MAIN PWB 4 5 2 5 5 1 5 2 System reset System reset is performed by detecting the rising and falling of the 5V source voltage at 1305 LED control circuit Green amber is lit with the control signal of the LED GREEN and LED AMBER signal pin 34 33 from 1304 Page 3 LA f1723 FP7317 L1702 vf17 FP17 6 EPROM Circuit diagram MAIN PWB 4 5 Data transfer between 1307 24LC16 and Scaller IC 1304 is effected through the IIC bus SCL pin 37 and SDA pin 36 of 1304 The data to be transferred to each device are stored in 1307 e 1304 control data e OSD related setting d
5. OSC Protection Detection e SST Ignition i Brightness Dimmin f kart gt ln Regulation Feed back lt LA 1723 FP7317 L1702 vf17 FP17 2 Trouble Shooting 1 No display of screen Screen is black color of LED is amber Does OSM display when you push MENU button When a signal isn t being inputted it is indicated with VIDEO INPUT It is indicated with OUT OF RANGE at the time of the frequency that it can t be distinguished v Preceed Nothing displays on screen section lt D o No Check if the sync signal from Computer is output and if the video cable is connected normally Input the sync signal of computer or NG OK change the cable AA Proceed Checking the resolution change IC movement section Page 13 LA f1723 FP7317 L1702 vf17 FP17 2 Nothing displays on screen Screen is black color of LED is green Is backlight lit NG gt Refer Checking the backlight unit section v Does computer output RGB video signals 1 Change pattern of video signal output on the host NG gt gt 2 Reconnect the video cable OK 3 Change the video cable y Check OSM menu is displayed on screen when you push the MENU key NG gt Check if the signal cable is connected between
6. converter circuit 22 10 Power board 23 3 Recommended Parts List Recommended Parts List 24 Page 2 LA f1723 FP7317 L1702 vf17 FP17 1 Circuit Description 1 Audio circuit Circuit diagrams Main PWB 5 5 Optional 1 1 1 2 Audio input The audio signal input received from the audio input terminal P305 is applied to the amplifier I309 of 1 and 9 through the low pass filter consisting of R361 R360 C370 C371 C361 and C363 In this audio circuit controls of Volume and mute are conducted The audio signal controlled by a VR determines the attenuation of output of the amplifiers Audio output The audio signal is output from the jack output terminal P306 to the internal speaker system 2 Interface board and panel power supply Circuit daigrams MAIN PWB 2 5 2 1 22 2 3 P301 connector A 5V power supply for LCD module CPU and logic is generated from the P301 connector 1301 pin 1 4 terminal regulator A 3 3V power supply for Scaler IC 1304 is generated from the 5V source 1301 pin 1 5 terminal regulator A 2 5V power supply for Scaler IC 1304 is generated from the 5V source Q302 Q303 ON OFF control for LCD
7. pulse train at pin 6 goes down to zero shutting Q803 off immediately 8 7 5 SCP If output terminal is short to ground photo transistor does not conduct hence Q806 does not conduct either Then oscillation of 1801 is stop shutting Q803 off immediately HPD K17AA Power Board Block Diagram Line Rec amp Filter Filter gt Power Transformer Outpur Rec amp Filter Don PWM Driver ur FB lt lt Page 11 LA f1723 FP7317 L1702 vf17 FP17 9 Inverter Circuit This unit operates on an output voltage of 15V from power source 9 1 Regulator Q101 geta 5VDC for 1101 power supply 9 2 UVP Q106 turns off when the Vin is under 10V Then pin 3 of1101 is pulled low and inverter off immediately That is the under voltage protection 9 3 Control IC 1101 OZ960S 9 3 1 Enable When pin 3 of 1101 is over 1 5V 1101 works If it is under 1 5V 1101 turns off 9 3 2 OSC When 1101 enabled R108 C115 pin 17 pin18 of1101 determine the operating frequency 9 3 3 SST C104 pin 4 of 1101 provides soft start function 9 3 4 Ignition R109 pin 8 of 1101 provides higher operating frequency for more striking voltage until regulation of feedback of lamp current C103 pin 1 of 1101 determine the striking time 9 3 5 Dimming control The divided voltage of R106 R105 R104 control the duty pulse of burst mode to drive Q105 and perform a wide dimmin
8. the OK MAIN PWB and LCD module v Failure Point NG Proceed Abnormal screen section OK The Cable is disconnected Next Page Page 14 LA f1723 FP7317 L1702 vf17 FP17 Continue y Check the 3 3 V power are supplied on 1301 pin 4 Check if the voltage on 1301 pin 1 that 1 NE is high level DC at 5V Failure point NG 1 Printed wire broke between P301 pin 7 8 and OK OK and 1301 2 Check power board y Failure point 1301 Failure y Failure point 1 The cable broke between P303 and LCD module 2 LCD module failure Page 15 LA f1723 FP7317 L1702 vf17 FP17 3 Checking the back light unit Is 22 5V supplied to inverter PWB Failure point ox NG 1 Inverter cable disconnection 2 Power board failure AA Check the BKLT_EN signal of the rectangle input P301 pin 2 at TTL high level Is a H level being output in the TTL level from 1304 pin 41 ER Or is BKLT_EN signal of the rectangle being output OK NG y Failure point Printed wire broke between 1304 pin 41 and R387 y Check the PWM signal of the input from 1304 pin 23 is a PWM signal Failure point OK NG gt 1 Printed wire broke between 1304 pin 23 and R301 2 1304 failure AA Failur
9. 1152 x 864 870 lt LINE lt 1031 1280 x 960 960 lt LINE lt 1027 O lt o e 1280 x 1024 C CS 73 User Control 7 3 1 Related ports and pin of 1304 GPIO3 1304 26 I MENU EXIT ENTER switch input 000000000 GPIO7 1304 32 I MINUS lt q switch input Auto Adj GPIO6_ 304 29 1 pros wiam GPIO21 1304 16 I POWER soft power switch input 7 3 2 Functions Control is effected for the push switches to be used when the user changes the parameters in order to modify the respective setting values Whether the switch has been pressed is identified with the switch input level that is turned L Each switch input port is pulled up at outside of ASIC Each parameter is stored in the EEPROM the contents of which are updated as required Page 6 LA f1723 FP7317 L1702 vf17 FP17 74 Control of definition converter LSI 74 1 Functions Major function of 304 are as follows 1 Expansion of the display screen 2 Timing control for various signal types 3 Power supply sequence LCD panel 75 PC bus control 7 5 1 PC controlled functions The following functional controls are effected by PC 1 Control of EEPROM 1307 for parameter setting 2 Control of audio preamplifier age LA f1723 FP7317 L1702 vf17 FP17 7 6 Power ON sequence When the POWER switch is pressed the POWER signal is turned L When this L potential is detected the CPU begins to establish the respect
10. ad Repair them No gt Yes y Check feedback circuit around 1802 1803 and the other components and repair them Page 23 D f1723 FP7317 L1702 vf17 FP17 1 Recommended Parts List Note 1 The components identified by A mark are critical for X ray safety Replace these with only the same parts specified 2 The components identified by mark are critical parts 3 There is only OTP IC at the model beginning FPR stage or before When it put in mass production and there must be Mask coming out Please checkyou have spart parts need please check BOM to get the last release part number and related information 6814700100 Panel AU M170EN05 ais fue 6841700900 Panel HD HT12E12 200 6814701300 Pane LG LM170E01 A5K2 Af fen eosa fenes somes foo om foom nw zeri e en eoon feia roa 1801 6442032800 IC 0Z960 6442022030 IC SG3842 TI 6131020600 XFMER TPW 1097 cae u L802 6111156136 ICOLCHOKE 15uH o CHOKE 15uH E 1804 6442035900 IC MP1410EP 1102 1105 6444011300 IC CMOS A09600 Page 24 La LITE ON TECHNOLOGY CORB 5 F No 16 Sec 4 Nanking E Road Taipei Taiwan Tel 886 2 25706999 Fax 886 2 25706888 URL www liteontc com tw Printed in Taiwan
11. ata e Other control data for service menu 7 Controller circuit Circuit diagram MAIN PWB 4 5 Tal 7 2 7 2 1 Scaller IC 1304 functions as the Controller The source voltage for the device are 3 3V and 2 5V and the system clock frequency is 14 318MHz Detection of POWER switch status The CPU identifies the ON status of the two power supplies The identification is made when the power supply is turned off For example if the power supply is turned off with the POWER switch the POWER switch must be turned on when activating the power supply again If the power supply is turned off by pulling out the power cord then this power supply can be turned on by connecting the power cord without pressing the POWER switch Display mode identification Functions 1 Display mode identification e The display mode of input signal is identified based on Table 1 e When the mode has been identified through the measurement of horizontal and vertical frequencies the total number of lines is determined with a formula of Horizontal frequency Vertical frequency Total number of lines Final identification can be made by examining the coincidence of the obtained figure with the number of lines for the mode identified from the frequency The boundary number of lines in each mode is shown in Table 2 e When the detected frequency if the sync signal has changed the total number of lines should be counted even though it is an identified frequen
12. cuit 12 age LA f1723 FP7317 L1702 vf17 FP17 2 Trouble Shooting 1 No display of screen Screen is black color of LED is amber 13 2 Nothing displays on screen Screen is black color of LED is green 14 3 Checking the back light unit 16 4 Abnormal screen 17 5 No OSM display 18 6 Abnormal plug and play operation 19 7 Checking the interface circuit of sync signal 20 7 1 Checking the control circuit of horizontal sync pulse 20 7 2 Checking the control circuit of vertical sync pulse 20 8 Checking the resolution change IC movement 21 9 Checking the DC DC
13. cy in the same mode 2 Power save mode The power save mode is assumed when the horizontal vertical signals are as specified below e If there is no horizontal sync signal input e If there is no vertical sync signal input e Ifthe horizontal sync signal is outside the measuring range of gm2121 e Ifthe vertical sync signal is outside the measuring range of gm2121 Page 4 LA 1723 FP7317 L1702 vf17 FP17 Table 1 Mode Resolution H freq Band Width Polarity KHz Miz 1 VGA640x 480 60Hz 31 47 asians 2 VESA 640 X 480 72Hz 37 86 31 5 Fa 3 VESA 640 X 480 75Hz 37 5 31 5 4 VGA720x 400 70Hz 31 47 28 322 5 VESA 800x600 60Hz 37 88 40 6 VESA 800x600 72Hz 48 08 Ile 7 VESA 800x600 75Hz 46 88 ee 8 MAC832x624 75Hz 49 72 57 283 9 VESA 1024x768 60Hz 48 36 65 10 VESA 1024x768 70Hz 56 48 ae kels 11 VESA 1024x768 75Hz 60 02 78 75 12 MAC 1152x870 75Hz 68 68 100 13 SUN 1152x90 76Hz 71 71 AAA 14 SXGA1280x 1024 60Hz 64 108 AES 15 SXGA1280x 1024 75Hz 80 135 ages LA f1723 FP7317 L1702 vf17 FP17 Table 2 the number of the lines Vsync distinction Indication resolution The number of the Distinction Vsync distinction lines 640 x 480 487 lt LINE lt 607 800 x 600 607 lt LINE lt 777 AA 832 x 624 640 lt LINE 1024 x 768 768 lt LINE lt 870 fV lt 63 Hz 68 Hz lt fV lt 73 Hz 73 Hz lt fV lt 78 Hz
14. e point 1 Inverter cable disconnection 2 Inverter of LCD module failure Page 16 LA 1723 FP7317 L1702 vf17 FP17 4 Abnormal screen Check the R G B video signal from computer input on D Sub R G B connector Failure point OK NG gt 1 No R G and B video signal output from host computer Check computer 2 Video signal cable disconnection AA Check the R G B input signals on 1304 pin 135 131 127 respectively that their level is 0 7Vp p maximum Failure point NG In the case of the Red signal A Green and Blue signal is the same path too OK 1 Printed wire broke between D Sub R and 1304 pin 135 2 R323 short 3 C317 open 4 R321 open v Check the horizontal sync pulse input to 1304 pin 101 at TTL level Failure point NG gt 1 Printed wire broke between 1304 pin 101 and P302 pin 8 OK 2 1304 failure AA Check the vertical sync pulse input to 1304 pin 100 at TTL level Failure point NG gt F OK 1 Printed wire broke between 1304 pin 100 and P302 pin 9 2 1304 failure v Process Checking the resolution change IC movement section Page 17 LA f1723 FP7317 L1702 vf17 FP17 5 No OSM display Check the input TTL level whether was changed when pressed function keys Failure point Printed wi
15. ent section 7 2 Checking the control circuit of vertical sync pulse Check the vertical sync signal on 1304 pin 100 TTL level NG Failure point 1 Video cable may have failed OK 2 Printed wire broke between P302 pin 9 and 1304 pin 100 3 FB302 R303 open 4 R307 C304 short y Process Checking the resolution change IC movement section Page 20 LA 1723 FP7317 L1702 vf17 FP17 8 Checking the resolution change IC movement Is there 3 3V supply on 1304 pin 124 136 132 128 113 108 104 106 110 115 14 30 90 143 157 ok NG gt Proceed Checking the DC DC converter circuit section Is there 2 5V supply on 1304 pin 119 117 20 43 79 98 138 NE Proceed Checking the DC DC converter circuit section OK AA Is 14 318MHz clock input to 1304 pin 102 and pin 103 at TTL level Is 14 318MHz clock output from NO X301 pin 1 at TTL level _NG gt i i ap OK Failure point X301 failure y Failure point Print wire broke between X301 pin 1 and 1304 pin 102 v Failure point 1304 failure Page 21 LA f1723 FP7317 L1702 vf17 FP17 9 Checking the DC DC converter circuit Check if the 5V is output from P301 pin 7 8 Printed wire broke between P301 pin oK Ne 7 8 and 1301 pin 1
16. erts energy for square wave from power source C805 to secondary side to generate 12V and 22 5V 8 4 Output The square wave from T802 is rectified by D809 D810 then filtered by C817 C822 to generate 22 5V and 12V respectively 8 5 Driver Q803 drive T802 from PWM control of 1801 for power converted 8 6 FB Negative feedback CKT consists of photo coupler 1802 and adjustable regulator 1803 It can maintain output voltages 22 5V and 12V at a stable level 8 7 PWM 87 1 Start When power is turned on C807 is charged a 15 volt and a starting current above 40uA to pin 7 of 1801 1801 starts to oscillate and outputs a pulse train through pin 6 to drive Q803 8 7 2 OPP When Q803 turns on C805 supplies a linearly increasing triangle current through the primary induc tance of T802 to the driver Q803 once the peak value of this current multiplied by R811 exceeds volt pulse train will be turn off immediately to protect Q803 T802 from being burned out 8 73 Regulation If output voltage 22 5V goes up the R terminal of 1803 gets more bias accordingly photo transistor and photo diode flows more current The voltage of pin 2 goes up too making the pulse width of pin 6 to become narrower So the output voltage 22 5V will be pulled down to a stable value 8 74 OVP If 22 5V goes up too much the induced voltage on pin 4 of T802 becomes large also Suppose that it is over 18 volts ZD801 conducts pin 3 of 1801 is pulled up over 1 volt The
17. g control for the CCFL The burst mode frequency is determined by C116 9 3 6 Regulation Pin 9 pin 10 of 1101 provide regulation of the CCFL current from feedback The non inverting reference pin 10 of 1101 is at 1 25V nominal 9 3 7 Protection Open lamp protection in the ignition period is provided through both pin and pin 2 of 1101 Removal of the CCFL during normal operation will trigger Q107 to turns on and shuts off the inverter This is latch function 9 3 8 Output drivers The configuration prevents any shoot through issue associated with bridge type power conversion applications Adjusting the overlap conduction between 1102 P MOSFET and 1103 N MOSFET 1102 N MOSFET and 1103 P MOSFET the CCFL current regulation is achieved same as 1104 and 1105 94 Full bridge swit ching Transformer 1102 1103 C123 1104 1105 C137 T101 T102 compose full bridge swit ching to convert DC into AC for driver the CCFL 9 5 Detection C128 C129 C130 C131 C132 C133 detect the output voltage and ensure a rated voltage by pin2 of 1101 Q108 Q109 ensure not a open lamp 9 6 Feedback D116 D117 D122 D123 D109 R120 R121 D108 sense the lamp current for negative feedback and regulation Inverter Board Block Diagram VCC Regulator VDD v Control IC 02960 gt Full bridge switching Transformer Lamp ON OFF gt UVP gt Enable Output driver
18. ive power supplies according to the sequence shown below Panel VCC gt 4 ie Panel DATA on B Back light gt Pf os fe Page 8 LA f1723 FP7317 L1702 vf17 FP17 7 7 Power OFF sequence When the POWER switch is pressed while the power supply is ON the POWER signal is turned L When this L potential is detected the CPU begins to turn off the respective power supplies according to the sequence shown below Panel VCC gt g E Panel DATA S D gt Back light mn Page 9 LA f1723 FP7317 L1702 vf17 FP17 7 8 List of GPIO Pin Assignments of the 1304 arian 5 une aio ie KULE 16 Re Power WH ONOFFMontorPowr apres AI Oea eos a VRR DO A WAT intercede OUT KULI n wma m wer Gero s oan m Ne BKLT ADJ WRn Al Al cs E Ooo Ooo e CE Oe ae as Aa WERE F H GPIO7 KEY_MINUS KEY _LEFT Enable H Address Input 6 7 Page 10 LA f1723 FP7317 L1702 vf17 FP17 8 Power Board Operation Therory 8 1 Line filter consists of C801 T801 C802 C803 C804 C837 C838 It eliminates high frequency interference to meet EMI s requirement 8 2 Rec amp Filter Bridge diode D801 converts AC source into pulsed DC This pulsed DC is smoothed and filtered by C805 R802 is an NTC negative thermal coefficient resistor used to reduce inrush current to be within safe range 8 3 Power transformer T802 conv
19. re broke between P308 pin 5 and 1304 pin 29 Printed wire broke between P308 pin 6 and 1304 pin 32 Printed wire broke between P308 pin 7 and 1304 pin 22 Printed wire broke between P308 pin 8 and 1304 pin 26 Printed wire broke between P308 pin 4 and 1304 pin 16 FB325 FB326 FB327 FB328 FB329 open RN302 RN301 short open 1304 failure 1 2 3 NG gt 4 OK 5 6 7 8 ee Wadi Proceed Checking the resolution change IC movement section Page 18 LA 1723 FP7317 L1702 vf17 FP17 6 Abnormal plug and play operation Confirm the output of serial data on 1303 pin 6 synchronize SCLK at TTL level Failure point NG 1304 failure Failure point The host machine isn t communicating in DDC2 mode The video cable may have failed or may not to have connections for DDC 1 2 3 Between 1303 pin 6 and P302 pin 12 may have failed 4 R310 R385 open 5 Cable failure Page 19 LA f1723 FP7317 L1702 vf17 FP17 7 Checking the interface circuit of sync signal 7 1 Checking the control circuit of horizontal sync pulse Check the horizontal sync signal on 1304 pin 101 TTL level Failure point NG 1 Video cable may have failed 2 Printed wire broke between P302 pin 8 OK and 1304 pin 101 3 FB303 R305 open 4 R306 C303 short AA Process Checking the resolution change IC movem
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