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4 Troubleshooting



4 Troubleshooting
4-1 First Checklist for Troubleshooting

1. Check the various cable connections first.
- Check to see if there is a burnt or damaged cable.
- Check to see if there is a disconnected cable connection or a connection is too loose.
- Check to see if the cables are connected according to the connection diagram.


2. Check the power input to the Video Board.


3. Check the voltage in and out between the SMPS Video Board, between the SMPS X, Y
Drive Board, and between the Logic Boards.




4-1
4 Troubleshooting

4-2 Checkpoints by Error Mode

4-2-1 No Power



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

Yes


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

Yes


Does proper B3.3V No
3 Check IC102.
appear at Pin 2 of IC111?

Yes

Does proper DC B1.8V No
4 appear at Pin 4 of Q802, Check Q802, Q803.
Q803?

Yes


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

Yes

Does proper DC 5V_P No
6 appear Check IC108.
at Pin 2 of IC108?

Yes

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

Yes


Does proper DC B5V No
8 Check IC120.
appear at IC120?


Yes


Check IC800 and IC400.




4-2
4 Troubleshooting

WAVEFORMS
1 2 3




4 5 6




7 8




4-3
4 Troubleshooting

4-2-2 No Picture (TV, Video, S-Video, Component)


Check R882(TV)
Check C884(Video) No
9 Check the input signal.
Check C851, C852(S-Video)
Check C511,C513,C515(Component)?


Yes


Check the IC800,IC500.




WAVEFORMS
9




4-4
4 Troubleshooting

4-2-3 No Sound


Does the signal appear at
Check the TU01 (TV Tuner)
C883,C880(TV) and No
C849, C850(PC) and Check the CN913 (Video, S-Video)
C881,C882(Component) Pin 117, Check the CN901 (Component)
of IC800 (VCTj)? Check the CN909


Yes


Does the signal appear at No
Check IC800.
R858, R859?



Yes


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


Yes


Replace the speaker.




4-5
4 Troubleshooting

Memo




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