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Service Manual

TFT LCD MONITOR

Model : L500B

DAEWOO ELECTRONICS CO., LTD
OVERSEAS SERVICE DEPT.

Summary of Contents for L500B

Page 1: ...ServiceManual TFT LCD MONITOR Model L500B DAEWOO ELECTRONICS CO LTD OVERSEAS SERVICE DEPT...

Page 2: ...G PRECAUTIONS 4 GENERAL INFORMATION 8 PIN CONNECTOR 9 OPERATION ADJUSTMENT 10 ALIGNMENT PROCEDURE 14 TROUBLE SHOOTING HINTS 15 BLOCK DIAGRAM 22 PCB LAYOUT 23 SCHEMATIC DIAGRAM 25 EXPLODED VIEW MECHANI...

Page 3: ...sharp solder points Be certain to remove all foreign materials u Implosion Protection TFT LCD in this monitor employs integral implosion protection system but care should be taken to avoid damage and...

Page 4: ...G Statements indicate a personal injury hazard immediately accessible as one reads the marking u Symbols in the manual This symbol indicates where applicable cautionary or other information is to be f...

Page 5: ...pacitors may result in a explosion hazard 2 Do not any spray chemicals on or near this instrument or any or its assemblies 3 Unless specified otherwise in this service manual clean electrical contacts...

Page 6: ...ally shorted together by conductive foam aluminum foil or comparable conductive material 7 Immediately before removing the protective material from the leads of a replacement ES device touch the prote...

Page 7: ...lder with an anti static suction type solder removal device or with desolder ing braid before removing the IC u Replacement 1 Carefully insert the replacement IC in the circuit board 2 Carefully bend...

Page 8: ...Observing diode polarity wrap each lead out of the new diode around the corresponding lead on the circuit board 4 Securely crimp each connection and solder it 5 Inspect the solder joints of the two o...

Page 9: ...And so this TFT LCD monitor has a maximum horizontal resolution of 1024 dots and a maximum vertical resolution of 768 lines for superior clarity of display By accepting analog signal inputs which lev...

Page 10: ...w Allow 20 minutes warm up time for the display before checking or adjusting only electrical specifica tion or function w Reform the leadwire after any repair work Pin Signal 1 Red 2 Green 3 Blue 4 G...

Page 11: ...lected function w Move cursor to the left window on the OSD window w Decrease the value of any selected function w Launch OSD On Screen Display MENU window w Move cursor to the high window on the OSD...

Page 12: ...11 OPERATION ADJUSTMENT u Key Process w When you choose the icon on the OSD window you can exit the OSD screen u Hot Key R G B Start...

Page 13: ...Is the noise displayed on the screen Is the noise displayed on the screen Is the noise displayed on the screen yet End Adjust the FIT SCREEN Perform the Adjust the until the screen is cleared AUTO TR...

Page 14: ...EN CONTROL Adjust the green color BLUE CONTROL Adjust the blue color H CENTER V CENTER Adjust the position of the display horizontally left or right and vertically up or down FIT SCREEN Make character...

Page 15: ...5Hz available only non interlace mode u Adjustment 1 Smart scaling set to 50 2 Contrast set to 100 3 Brightness set to 50 4 Switching to factory alignment mode Press power key with down menu key t at...

Page 16: ...G HINTS 1 Abnormal mode detect YES Abnormal mode detect Trouble video input circuit Check input H Sync of TDA8752 NO YES Trouble in the TDA8752 Check waveforms of 84 pin of TDA8752 correct YES Trouble...

Page 17: ...video or No raster Power LED ON OFF Trouble in adapter Check output voltage of adapter YES Is the 5VS line normal NO Trouble in SQ8 and its ambient circuit NO YES YES Is the pulse of pin9 of the IC1...

Page 18: ...the Q10 or MX88281 If it s trouble in the MX88282 change the main B D Check the output of the Q10 or 3 pin of CN1 2 5V 2 5V Check the 12V of the main power CN1 1 pin 12V check YES Check the DC AC out...

Page 19: ...missing Check the output signal of the MX88281 and 74act573 Is OSD color normal NO YES Replace the main B D Are the R G B digital 8 bit output of the U17 TDA8752 YES Check video signal cable or video...

Page 20: ...Check reset signal 9 pin of micom and its ambient circuit Check output voltage 5V 3 3V 12V NO Trouble in the Q9 and its ambient circuit NO YES Trouble each trouble item Check on off signal of micom YE...

Page 21: ...ING HINTS 6 Abnormal video Abnormal video Check the output of MX88281 Is the OSD normal NO YES YES Check the control and data signal of SDRAM Is LCLK output the L1 waveform normal Check connection of...

Page 22: ...O YES U8 2 pin output 12V check YES YES LVCC 3 3V check No raster NO YES Is OSD normal Change the contrast control value to maximum NO YES Are the contrast controls maximum NO YES YES Are the output s...

Page 23: ...plifier TDA8752 3 RGB signal 15PIN DSUB CONNECTOR PRE AMP Controller Buffer 2 H V sync ADC PLL Sampling clock KM416S1020CT X 3 16M SDRAM X 3 Scaling Controller Red Micom 78 E58 I2C bus 12V adapter AC...

Page 24: ...25 SCHEMATIC DIAGRAM u MAIN88281A...

Page 25: ...26 SCHEMATIC DIAGRAM u TOP CIRCUIT...

Page 26: ...27 SCHEMATIC DIAGRAM u BUFFER...

Page 27: ...28 SCHEMATIC DIAGRAM u POWER DC DC...

Page 28: ...29 SCHEMATIC DIAGRAM u MEMORY...

Page 29: ...30 SCHEMATIC DIAGRAM u MICOM...

Page 30: ...31 SCHEMATIC DIAGRAM u RGB SYNC...

Page 31: ...32 SCHEMATIC DIAGRAM u TDA8752A...

Page 32: ...33 EXPLODED VIEW MECHANICAL PARTS LIST...

Page 33: ...omponents use only manufacturer s specified parts Abbreviation of Description RESISTOR Description Example CAPACITOR Description Example Allowance F 1 J 5 K 10 M 20 G 2 Fig Index Part No Description R...

Page 34: ...5V 0 1MF Z 2012 C082 HCFK103ZCA C CHIP CERA 50V Y5V 0 01MF Z 2012 C083 HCFK103ZCA C CHIP CERA 50V Y5V 0 01MF Z 2012 C084 HCFK104ZCA C CHIP CERA 50V Y5V 0 1MF Z 2012 C085 HCFK104ZCA C CHIP CERA 50V Y5V...

Page 35: ...ERA 50V Y5V 0 1MF Z 2012 C25 HCFK104ZCA C CHIP CERA 50V Y5V 0 1MF Z 2012 C27 HCFK104ZCA C CHIP CERA 50V Y5V 0 1MF Z 2012 LOC PART CODE PART NAME PART DESC C273 HCQK102JCA C CHIP CERA 50V CH 1000PF J 2...

Page 36: ...RTK Q16 DKDS226RTK DIODE CHIP KDS226 RTK Q17 DKDS226RTK DIODE CHIP KDS226 RTK LOC PART CODE PART NAME PART DESC Q2 TKTC3875SY TR CHIP KTC3875SY RTK Q3 TKTC3875SY TR CHIP KTC3875SY RTK Q4 1K1A7805P1 I...

Page 37: ...1MF Z 2012 SC6 HCFK103ZCA C CHIP CERA 50V Y5V 0 01MF Z 2012 SC7 HCFK103ZCA C CHIP CERA 50V Y5V 0 01MF Z 2012 SC8 HCFF105ZEA C CHIP CERA 16V Y5V 1MF Z 3216 SD1 DKDS181RTK DIODE CHIP KDS181 RTK LOC PAR...

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