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Repair guides and support for your LG TV.

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turns on and immediatly shuts off

A few years ago it was doing the same thing and I would unplug from the back of the tv and restart and then it worked fine.

Lately though, the red light is on when I turn on with the remote there is a click, the red light turns off, the screen goes gray for a moment then you hear that click again and the red light comes back on and the screen goes black.

It's an LG plasma, 42PT350, its from 2011, maybe it's reached it's life?

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tried turn it on and off from the front panel, same result; also does the same if you unplug it and plug it back in. Took the back off and dusted, still the same.

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The gray screen is likely the backlight. The on/off is likely a current overload.

The possibilities = start by inspecting all electrolytic capacitors for bulging or leakage. Replace any that are suspect.

Next, monitor power supply voltages to see if any don't come up to value b4 it turns off.

It is possible the backlight LEDs have a problem and are the cause even though it looks like they are coming on.

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Thanks Bill, I'll try that and post an answer tomorrow.

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Thank you for that very informative answer! So, yesterday after opening up the back I cleaned the circuit boards with one of those cans of air pressure, then I left it unplugged and open all day. This morning I checked over the capacitors as you suggested and couldn't really see any problems. I plugged it back in and it worked! Wow! I unplugged and put the back on and everything seems to be working now.

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