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LG 42LC55 board No EAY38640201 Backlight flashover, any help appreciated

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rubbishrat:
Hi all, my first time posting here! I used to repair TVs for a living years ago but I'm retired now, I've been given an old LG 42LC55 that will start briefly and shut down after a second or so, the picture looks OK when its on, I'm new to this computer and LCD tech so please be patient with me. During the brief time the set starts up there is high voltage flashover from one of the backlight leads to chassis, a bit like we used to see when the eht trippler failed. I didn't expect to see this and I can't find any faulty components checking cold. all the semiconductors check out fine, the lt caps esr all check ok. could this be the ballast transformer ?? or maybe the FAN7382 driver chip ?this main power board includes the backlight components. Any help appreciated. Cheers, Pete   

sparky:
hi
check the caps on psu they can cause this  some show signs
of bulging
dave

watteau:
Hello,
There is a service bulletin for intermittent problems
on this model (ceratec filters), this might be causing the problem.
If you search previous posts using 'ceratec' you should find
more info.
Regards,
John.

Turnip:
Hi Pete,

Curious one - never seen flashover from backlight leads to chassis or tube insulation problems with anything bigger than a 24 inch (where it's common with top/bottom tubes in metal housings)

Guess some PS over voltage prob where inverter shuts down sensing fault - Chris.

sparky:
hi
if you can split the screen you should see were
 the connecters have been arcing and burning
dave

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