CONFIDENTIAL

5 Troubleshooting

5-1 No Power

Does proper DC 28 V appear at DC jack connected to CN112? No
Check SMPS PCB and Adapter.
Yes Does proper DC 5 V appear at Pin 1 of IC849 and Pin 2 of IC828, IC830, IC852? Yes
Check IC849, IC830 and IC828, IC852.
Does proper DC 12 V appear at Pin 2 of IC829?

Check IC829.

Does proper DC 2.5 V appear at Pin 2 of IC804, IC806 and IC807?
Check IC804, IC806 and IC807.
Does proper DC 3.3 V appear at Pin 2 of IC800, IC801 and IC805?
Check IC800, IC801 and IC805.

Check IC811 and IC817.

LW29A13W/LW40A13W
5-2 No Video (PC Analog Signal)

Power indicator is green

Does the signal appear at Pin 7, 15 and 22 of IC203?
Check the R, G, B signal line and related the R, G, B signal line.
Does the clock pulse appear at Pin 30 and 31 of IC203?
Check IC203 and related circuit of IC203.
Does the colck pluse appear at Pin 4, 10 of IC838?
Check related circuit of IC838.

Replace LCD Panel.

5-3 No Video (PC Digital Signal)
Does the signal appear at Pin 80, 81, 85, 86, 90, 91, 93 and 94 of IC833? Yes Does the signal appear at RA603, RA631, RA632 and RA633? Yes
Check R2018, 2019, 2020, 2021, 2022, 2023, 2024 and 2025.
Check IC833 and related circuit of IC833.
5-4 No Picture (CVBS, S-VHS, Scart Video)
Check Pin 13, 15 (RF_CVBS1, FR_CVBS2) of CN622? Pin 9 (Scart1_Vin) of CN601 Pin 9 (Scart2_Vin) of CN621 Yes
Check Tuner, Scart1, Scart2 connector.
Check Pin 3 (YIN), 5 (CIN) and 7 (VCR) of CN601?
Check RCA, S-VHS connector.

IC842 (VSP9437B)?

Check related circuit of IC842 and replace IC842.
IC308, IC309 and replace it.
No Check Pin 1 and 6 of CN113.

5-5 No Sound (LW29A13W)

Does the Low signal at Pin 16 and of IC702?
Does the Low signal at Pin 17 of IC702

Replace IC702.

Check Pin 67 (QSS_IF), Pin 53, 54 (Scart1_In), Pin 50, 51 (Scart1_In), Pin 48, 47 (RCA), of U458 (MSP3451)?

Check CN703.

Replace IC831 (MSP 3451).

No Check Pin 1 of CN624.

5-6 No Sound (LW40A13W)
Does the Low signal at Pin 16 and of IC13?
Does the Low signal at Pin 17 of IC13

Replace IC13.

Check Pin 50, 52 (QSS_IF), Pin 44, 45 (RCA), Pin 41, 42 (Scart1_In), Pin 38, 39 (Scart1_In) of IC18?

Check CN629.

Does the Digital signal at Pin 8, 9 and 10 of IC15?
Check IC18 and related IC18?
Check IC15 and realted IC15.
5-7 LW40A13W (Digital Sound - coaxial optical)
Does the Low signal at Pin 16 of IC13?
Does the Low signal at Pin 17 of IC13?
Does the Digital signal at Pin 41 (coaxial), 43 (optical) IC15?

Check the CN627.

Does the Digital signal at Pin 11, 12, 13 of IC15?
Check IC15 and related IC15.

Check IC14.

CONFIDENTIAL
3 Disassembly and Reassembly
This section of the service manual describes the disassembly and reassembly procedures for the LW29A13W/LW40A13W monitor. WARNING: This monitor contains electrostatically sensitive devices. Use caution when handling these components.

3-1 Disassembly

Cautions:1. Disconnect the monitor from the power source before disassembly. 2. Follow these directions carefully; never use metal instruments to pry apart the cabinet. 1. Remove 4 screws of the cover rear.
2. Remove the stand from LCD-TV.

LW29A13W/LW40A13W

3. Remove 4 screws of the cover rear.

Pull the cover rear.

3-2 Reassembly
Reassembly procedures are in the reverse order of Disassembly procedures.