Troubleshooting - LG 42LG5000 Service Manual

TV/CATV doesn't display
Check TU500 Pin15(Video output),
Pin16(Sound output)
Can you see the normal signal?
YES
Check the output of TR(Q503).
Can you see the normal waveform?
YES
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.
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Only for training and service purposes

TROUBLESHOOTING

Could you measure voltage of
NO
TU800 & IIC lines?
Are they all normal?
You should replace TUNER.
NO
You should decide to replace TR(Q503)
or not.
After checking the Power of Main
NO
IC(IC100) you should decide to replace
Main IC or not.
- 22 -
NO
You should check power line
YES
& IIC lines.
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