LG L1972H Service Manual Download Page 14 | Manualshive

Page: 14 / 36

background image

- 14 -

TROUBLESHOOTING GUIDE

Copyright

2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

LGE Internal Use Only

1. NO POWER

NO POWER

(POWER INDICATOR OFF)

CHECK IC501

NO

NO

CHECK POWER BOARD,
AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE

CHECK U901(3.3V)
U902(1.8V) LINE

NO

CHECK CRYSTAL(X501)

YES

YES

YES

CHECK J905 VOLTAGE

PIN5,6 (5V)?

IS U901 PIN2(3.3V)

U902 PIN2(1.8V)

CHECK X501 PIN127

PULSE

1

2

1

3

1

4

Waveforms

1

J905-#5,6

2

IC901-#2

3

IC902-#2

4

IC501-#127

«
...
12
13
14
15
16
...
»

Summary of Contents for L1972H

Page 1: ...ANUAL Website http biz LGservice com CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL CHASSIS NO LM74B MODEL L1972H L1972H PFS A OAP To apply the MSTAR Chip Same model for Service Internal Use Only ...

Page 2: ...eserved Only for training and service purposes LGE Internal Use Only CONTENTS CONTENTS 2 PRECAUTION 3 SPECIFICATION 7 DISASSEMBLY 9 ADJUSTMENT 10 SERVICE OSD 13 TROUBLE SHOOTING 14 BLOCK DIAGRAM 21 EXPLODED VIEW 24 REPLACEMENT PARTS LIST 26 SVC SHEET ...

Page 3: ...s pencil or pen as this may result in damage to the panel Protect the module from the ESD as it may damage the electronic circuit C MOS Make certain that treatment person s body are grounded through wrist band Do not leave the module in high temperature and in areas of high humidity for a long time The module not be exposed to the direct sunlight Avoid contact with water as it may a short circuit ...

Page 4: ...eat sinks are correctly installed 8 Always connect the test receiver ground lead to the receiver chassis ground before connecting the test receiver positive lead Always remove the test receiver ground lead last 9 Use with this receiver only the test fixtures specified in this service manual CAUTION Do not connect the test fixture ground strap to any heat sink in this receiver Electrostatically Sen...

Page 5: ... by gently prying up on the lead with the soldering iron tip as the solder melts 2 Draw away the melted solder with an anti static suction type solder removal device or with solder braid before removing the IC Replacement 1 Carefully insert the replacement IC in the circuit board 2 Carefully bend each IC lead against the circuit foil pad and solder it 3 Clean the soldered areas with a small wire b...

Page 6: ... and carefully crimp it around the IC pin Solder the IC connection 4 Route the jumper wire along the path of the out away copper pattern and let it overlap the previously scraped end of the good copper pattern Solder the overlapped area and clip off any excess jumper wire At Other Connections Use the following technique to repair the defective copper pattern at connections other than IC Pins This ...

Page 7: ...ital SOG 3 2 Video Input Signal 1 Type R G B Analog 2 Voltage Level 0 0 71 V a Color 0 0 0 Vp p b Color 7 0 0 467Vp p c Color 15 0 0 714Vp p 3 Input Impedance 75Ω 3 3 Operating Frequency Horizontal Analog 30 83kHz Horizontal Digital 30 71kHz Vertical 56 75Hz 4 Max Resolution D sub Analog 1280 x 1024 75Hz Digital 1280 x 1024 60Hz 5 POWER SUPPLY 5 1 Power AC 100 240V 50 60Hz 0 8A 5 2 Power Consumpti...

Page 8: ... 16 80 160 800 x 600 V Lines 75 0 625 600 1 3 21 7 H Pixels 57 283 49 725 1152 832 32 64 224 832 x 624 V Lines 74 55 667 624 1 3 39 8 H Pixels 65 0 48 363 1344 1024 24 136 160 1024 x 768 V Lines 60 0 806 768 3 6 29 9 H Pixels 78 75 60 123 1312 1024 16 96 176 1024 x 768 V Lines 75 029 800 768 1 3 28 10 H Pixels 100 0 68 681 1456 1152 32 128 144 1152 x 870 V Lines 75 062 915 870 3 3 39 11 H Pixels 9...

Page 9: ...ly for training and service purposes LGE Internal Use Only DISASSEMBLY Disassemble Hinge cover Remove the screws Remove the screws 1 2 3 Disassemble back cover 5 1 Pull the front cover upward 2 Then let the all latches are separated 3 Put the front face down 4 ...

Page 10: ...ing Preset Mode and Reset mode EEPROM is initialized when AC Power is ON first If the change of FOS data is needed after M P it is possible by writing Mode Data with EEPROM write command or modifying the Mode Data in MICOM itself Caution Must keep power on more than 3 seconds after AC Power on first time 3 2 4 Color coordinates adjustment and Luminance adjustment 3 2 4 1 Color coordinates adjustme...

Page 11: ...ting 8 color Bar Pattern 256 Gray Scale pattern 3 2 5 7 DPM operation confirmation Check if Power LED Color and Power Consumption operates as standard Measurement Condition 230V 50Hz Analog Confirm DPM operation at the state of screen without Video Signal refer to Spec at Page 11 3 2 5 8 DDC EDID Write Set as Aging mode ON by commanding AGING_ON OFF command code Digital part EDID data Confirm whet...

Page 12: ...etup Windows 2000 XP Need to Port Setup This program is available to LCD Monitor only 1 Port Setup a Copy UserPort sys file to c WINNT system32 drivers folder b Run Userport exe c Remove all default number d Add 300 3FF e Click Start button f Click Exit button 2 EDID Read Write 1 Run WinEDID exe 2 Edit Week of Manufacture Year of Manufacture Serial Number a Input User Info Data b Click Update butt...

Page 13: ...OSD 1 Turn off the power switch at the front side of the display 2 Wait for about 5 seconds and press MENU POWER switch with 1 second interval 3 The SVC OSD menu contains additional menus that the User OSD menu as described below a Auto Color W B balance and Automatically sets the gain and offset value b NVRAM INIT EEPROM initialize 24C08 c CLEAR ETI To initialize using time d AGING Select Aging m...

Page 14: ...NO POWER NO POWER POWER INDICATOR OFF CHECK IC501 NO NO CHECK POWER BOARD AND FIND OUT A SHORT POINT AS OPENING EACH POWER LINE CHECK U901 3 3V U902 1 8V LINE NO CHECK CRYSTAL X501 YES YES YES CHECK J905 VOLTAGE PIN5 6 5V IS U901 PIN2 3 3V U902 PIN2 1 8V CHECK X501 PIN127 PULSE 1 2 1 3 1 4 Waveforms 1 J905 5 6 2 IC901 2 3 IC902 2 4 IC501 127 ...

Page 15: ...SD IS NOT DISPLAYED CHECK POWER BOARD LIPS CHECK J905 VOLTAGE PIN5 6 5V NO NO NO NO 1 CONFIRM BRIGHTNESS OSD CONTRL STATUS 2 CHECK SCALER DIM ADJ PORT 3 CHECK SCALER LAMP ADJ PORT CHECK J905 PIN10 POWER BOARD LIPS CHECK PULSE AS CONTACTING PROBE TO THE LAMP WIRE OF THE LCD MODULE REPLACE LCD MODULE YES 1 3 2 4 YES YES YES Waveforms 1 J905 5 6 2 J905 9 4 LAMP CURRENT 3 3 J905 9 Brightness 100 J905 ...

Page 16: ... 127 128 SOLDERING CONDITION 2 CHECK X501 3 TROUBLE IN IC501 CHECK IC501 PIN114 3 3V PIN21 1 8V NO NO NO CHECK U901 3 3V U902 1 8V IC501 PIN 127 128 14 3MHZ CHECK CONNECTION LINE FROM D SUB TO IC501 TROUBLE IN CABLE OR LCD MODULE YES YES NO RASTER OSD IS NOT DISPLAYED CHECK U501 PIN32 H SYNC AND PIN33 V SYNC IS PULSE APPEARED AT SIGNAL PINS YES 1 Waveforms 1 IC501 30 ...

Page 17: ...training and service purposes LGE Internal Use Only 4 TROUBLE IN DPM TROUBLE IN DPM TROUBLE IN IC501 CHECK PC PC IS GOING INTO DPM MODE NO CHECK H V SYNC LINE NO YES CHECK R718 AND R719 SYNC APPEARED CHECK IC501 PIN 32 33 SYNC PULSE YES 1 H SYNC 2 V SYNC Waveforms 1 2 ...

Page 18: ...POWER INDICATOR OFF NO Trouble in Fuse F101 CHECK 5V 12V Line NO NO Check BD101 Check U101 Pin7 9 10V Check D102 Trouble in Q101 NO Trouble in D201 D202 YES CHECK Fuse F101 OK CHECK C101 Voltage AC110V 160Vdc AC220V 304Vdc CHECK U101 Pin6 Waveform Square wave Come out Check Q101 Drain Waveform Check D201 D202 Voltage YES YES YES YES NO ...

Page 19: ...t Main Board CHECK T301 T302 NO NO Check Q301 Q302 Check the waveform of U301 Pin11 12 19 20 Check the waveform of U301 Pin11 12 19 20 NO If waveform is no problem Check Q303 Q308 Or Trouble in U303 U304 YES CHECK P201 Pin9 3 3V Check U301 Pin3 5V Check U301 Pin2 OVP Less than 1 8V Check U301 Pin10 CMP Less than 2 75V Check U303 U304 Drain waveform YES YES YES NO YES ...

Page 20: ...1 LIPS Filter 5V 15V 5V Regulator 3 3V Vcc 5V Inverter 4Lamps 15V Flash ROM DVI D DVI TMDS KEY 1 8V 1 8V 3 3V Module SDA SCL EEPROM EDID EEPROM System 3 3 EEPROM EDID Crystal 14 318MHz Crystal Location No X501 135Mhz Dual Interface Engine Display Processing Engine Response Time Enhancement LVDS Panel Interface OSD Clock Generator MCU DRAM TSUMO56WHJ LF 3 3V 5V ...

Page 21: ...K DIAGRAM POWER LAMP High Low Module Vcc Main Board Scaler DC DC converter POWER INVERTER Inverter Control IC P ch Inverter Trans SMPS N ch Lamp Current Feedback Over Voltage Protection Power Control IC Feedback Line Filter L N Drive Block 15V 5V 15V 5V Inverter On OFF 3 3V Dimming Lamp Current Control Aux Drive 15V Start ...

Page 22: ...og to digital interpolates input to 1280 X 1024 resolution signal and outputs 8 bit R G B signal to transmitter 2 Power Part This part consists of the one 3 3V and one 1 8V regulators to convert power which is provided 5V in Power board 15V is provided for inverter 5V is provided for LCD panel Also 5V is converted 3 3V and 1 8V by regulator Converted power is provided for IC in the main board The ...

Page 23: ... part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk capacitor 3 Energy Transfer This part function is for transfer the primary energy to secondary through a power transformer 4 Output rectifier and filter This part function is to make a pulse width modulation control and to provide the driver signal to power switch to adjust the duty cycle duri...

Page 24: ...EW Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 300 200 460 510 470 520 450 440 430 420 900 904 500 310 320 911 910 912 913 330 400 410 903 902 901 ...

Page 25: ...per MOLD SANTOPRENE SUPPORT RUBBER L1972 Lx7W Bottom Rubber 430 MGJ38598201 Plate Shield PRESS SPTE 0 3 SHIELD SPTE L1972 L1954 LAMP WIRE SHIELD 440 ADV33707201 Frame Assembly L1954 L1972 Dual LM57B 19 Rear Frame Assy 450 MCK38597501 Cover MOLD PC ABS L1972 ABS L1972 L1954 Lx7W VESA BRACKET 460 MCK38597701 Cover MOLD PC ABS L1972 ABS L1972 L1954 Lx7W LIPS BRACKET 470 MGJ39022602 Plate Metal PRESS ...

Page 26: ...amic RadialDCG150J26 C402 EAE36975601 Capacitor Ceramic RadialDCG150J26 C403 EAE36975601 Capacitor Ceramic RadialDCG150J26 C404 EAE36975601 Capacitor Ceramic RadialDCG150J26 C407 0CK22201510 Capacitor Ceramic RadialDCH222K43 C408 0CK22201510 Capacitor Ceramic RadialDCH222K43 C409 0CK22201510 Capacitor Ceramic RadialDCH222K43 C410 0CK22201510 Capacitor Ceramic RadialDCH222K43 C411 0CH6152K406 Capac...

Page 27: ...e RectifierIN4007 L 1KV 1V 5U D103 0DSGF00019A Diode Switching1N4148 1V 100V 150 D104 0DRTW00274A Diode Rectifier2A05 600V 1V 50UA D105 0DRTW00274A Diode Rectifier2A05 600V 1V 50UA D106 0DRTW00274A Diode Rectifier2A05 600V 1V 50UA D107 0DRTW00274A Diode Rectifier2A05 600V 1V 50UA D201 0DRTW00280A Diode RectifierMBRF10200CT 200V 9 D202 EAH36977701 Diode RectifierSR306 TSC 60V 700M D203 EAH36977701 ...

Page 28: ...ChipMCR10EZHF182 1 8KOHM R207 0RH1001D622 Resistor ChipMCR10EZHJ102 1KOHM 5 R208 0RH6800D622 Resistor ChipMCR10EZHJ681 680OHM R209 0RH1001D622 Resistor ChipMCR10EZHJ102 1KOHM 5 R211 0RJ1001G476 Resistor ChipMCR18EZHF1001 1KOHM R3 0RJ1201D677 Resistor ChipMCR03EZPJ122 1 2KOHM R301 0RH4701D622 Resistor ChipMCR10EZHJ472 4 7KOHM R302 0RD0222Q609 Resistor Carbon FilmRDM94T1J22R0 R303 0RH1000D422 Resist...

Page 29: ... ChipMCR03EZPJ472 4 7KOHM R730 0RJ2200D677 Resistor ChipMCR03EZPJ221 220OHM R731 0RJ2200D677 Resistor ChipMCR03EZPJ221 220OHM R732 0RJ1000D677 Resistor ChipMCR03EZPJ101 100OHM R733 0RJ1000D677 Resistor ChipMCR03EZPJ101 100OHM R735 0RJ2001D677 Resistor ChipMCR03EZPJ202 2KOHM 5 R736 0RJ4701D677 Resistor ChipMCR03EZPJ472 4 7KOHM R737 0RJ4701D677 Resistor ChipMCR03EZPJ472 4 7KOHM R738 0RJ4701D677 Resi...

Page 30: ...36896701 Transformer SwitchingEEL 22 EEL22 TH101 6322A00035A Thermistor NTC10D2 07 10OHM 15 2 X501 6212AA2004F CrystalHC 49 U 14 31818MHZ 30PPM LOC NO PART NO DESCRIPTION SPECIFICATION 30 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 31: ... 31 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only PRINTED CIRCUIT BOARD MAIN TOP MAIN BOTTOM ...

Page 32: ... 32 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only CONTROL POWER ...

Page 33: ... 33 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 1 SCALER ...

Page 34: ... 34 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 2 POWER WAFER ...

Page 35: ... 35 Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 3 CONTROL ...

Page 36: ...Jun 2007 P NO MFL38456753 Printed in Korea ...

Reviews:

No comments

Related manuals for L1972H

Brand: D-Link Pages: 24

Brand: Calrec Pages: 132

Brand: Garmin Pages: 26

Heart Rate Monitor

Brand: Garmin Pages: 8

Brand: FDI Pages: 15

Brand: Luminator Pages: 34

Brand: Viotek Pages: 16

Brand: Wohler Pages: 24

ProLite XU2793HS

Brand: Iiyama Pages: 39

migra MPB EN TCP/IP

Brand: microSYST Pages: 51

Brand: Fujitsu Siemens Computers Pages: 28

Brand: AOC Pages: 1

Brand: Duemmegi Pages: 11

Brand: AOC Pages: 64

Brand: I-Inc Pages: 23

LINETRAXX RCMS460-D

Brand: Bender Pages: 8

Brand: SAFECONTROL Pages: 2

Brand: Lamp Pages: 63

Brands by name

0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Popular brands

Load more brands