LG 60PK250/550 series Plasma; no standby

[videobruce]

When power cord is inserted into a outlet all I get are two flashes of the power LED, then nothing. Completely dead. No clicking.

The power supply, Y & Z boards all have been removed and inspected under a magnifying lamp for bulged caps, cold solder joints & burn marks and nothing found. All connectors were also inspected and reseated 3 or 4 times.

Initially when the set died a repair shop came out and inspected the power supply board and 'hit' a few possible suspicious solder joints. The set worked for a month or so, then died again. What also was happening, the set could be left on for 2-3 days, but when turned off and later back on (unknown time frame) it wouldn't power up.

They and I assume it's the PS board, but one huge problem is, there are no schematics that I can find on this series from Goldstar of theses boards. I have three similar service manuals, but the only schematics are for the control & main boards. No idea why Goldstar doesn't/didn't supply what should be in a service manual is beyond me.

Anyway, any ideas here? I have done a fair amount of reading and I have seen nothing with the scenario.

[videobruce]

Re: LG 60PK250/550 series Plasma; no standby

The set is from 2010 and was left one for hours on end (a real poor practice) with no one watching. There was a fair amount of dust collected everywhere which was removed (not by a can of compressed air). The only discoloration I saw was on the reap internal cover. But, nothing I would consider unusual.
Again, the boards were not discolored at all.

[videobruce]

Re: LG 60PK250/550 series Plasma; no standby

Would heating up (or freezing) any of the components help find the problem? I see that mentioned a number of times. Any component temperature issues were always running hot, not cold from my experience.