LG Plasma - 42PX4MVH-TA

[burntfingers]

Hi, guys.
Customer brought this set with complaint that it switches on in the morning and works fine for as long as it is on.
When switched off and on again - on the stand by button - sound is OK, but picture won't come on for a while - depending on how long has it been on, sometimes taking HOURS.

But it always starts fine the next morning.

I've inspected the unit visually and see no culprit caps.
Also have no diagram.
Has anybody had this problem before?

[tom66]

Re: LG Plasma - 42PX4MVH-TA

I would check the Vs and Va voltages and see if they are stable when turned on.

[burntfingers]

Re: LG Plasma - 42PX4MVH-TA

Thanks, Tom, for your suggestion.
Well, this morning I went check those voltages and also the 5v and they are very stable indeed.
I actually reduced Vs and Va slightly, but with no luck.
The picture came up normal from cold, and keeps going fine for as long as it is on.
If switched off and on it doesn't show picture for a long time.
Customer informed that it might take HOURS to come back - sound is always normal.

I already checked with Screenvision for the kit they have for this set - YSUS and ZSUS but very expensive.
Customer will not accept the quote.

I'm going to let the set cool down and then use an air dryer to warm up those boards one at a time before turning the set on, to try locate the fault.
What do you think about this idea?

[tom66]

Re: LG Plasma - 42PX4MVH-TA

I would also check if the screen stays glowing in a dark room when no picture is displayed.