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5 Troubleshooting
5-1 No Power

Does proper DC 14V/5V No
1 appear at Pin 3. Pin 9 of Check CN803 Pin3, Pin9 in I/P
CN100? Board.


Yes


Does proper DC A5V No
2 Check IC101 and IC105.
appear at FT144?



Yes


Does proper B3.3V No
3 Check IC111.
appear at Pin 2 of IC111?



Yes



Does proper DC B1.8V No
4 Check IC112.
appear at Pin 4 of IC112?



Yes


Does proper DC B8V No
5 Check IC109.
appear at FT130?




LW17M24C/LW20M21C 5-1
5 Troubleshooting



Yes


Does proper DC 5V_P No
6 appear Check IC104.
at Pin 2 of IC104?


Yes



Does proper DC 9V_S No
7 Check IC110.
appear at FT127?



Yes


Does proper DC B5V No
8 Check IC108.
appear at FT131?



Yes


Check IC704 and IC802.




5-2 LW17M24C/LW20M21C
5 Troubleshooting

WAVEFORMS
1 2 3




4 5 6




7 8




LW17M24C/LW20M21C 5-3
5 Troubleshooting

5-2 No Picture (TV, Video, S-Video, DVD)

Check C800(TV)
Check C822(Video) No
9 Check the input signal.
Check C824(S-Video)
Check C821(SCART)?


Yes


Check the IC802.




WAVEFORMS
9




5-4 LW17M24C/LW20M21C
5 Troubleshooting

5-3 No Sound

Does the signal appear at
Pin 110 (Tuner sound signal) and (RF) Check Tu01 (TV Tuner).
No
Pin 113, 114 (VCR sound) and (Video) Check the CN913.
Pin 119, 120 (SCART) Pin 117, (SCART) Check the CN901.
118 (PC) of IC802 (VCTj)?


Yes


Does the signal appear at Pin No
Check IC802.
123, 124 of IC802 (VCTj)?



Yes



Does the signal appear No Check the IC600 (Audio amp)
at Pin 2, 5 of Pin 16, 19 IC600? and related circuit of IC600.



Yes


Replace the speaker.




LW17M24C/LW20M21C 5-5
5 Troubleshooting

Memo




5-6 LW17M24C/LW20M21C