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TROUBLESHOOTING

TV/CATV doesnt display

Check TU500 Pin15(Video output),
Pin16(Sound output)
Can you see the normal signal?
Check the output of TR(Q503).
Can you see the normal waveform?
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
YES
NO Could you measure voltage of
TU800 & IIC lines?
Are they all normal?
YES
NO You should check power line
& IIC lines.
YES
You should replace TUNER.
NO You should decide to replace TR(Q503)
or not.
NO After checking the Power of Main
IC(IC100) you should decide to replace
Main IC or not.
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.