LG 60PM6700-UB Plasma - Sporadic Powers On With Sound, But No Video.

[grimacelord]

Had a family member bring this to me to see if I could do anything with it. He says that sometimes, when he turns the TV on, there will be audio, but no image. It may go on like this for an hour or so before suddenly, the image will return. He says usually this only happens after having previously watched TV for awhile earlier in the day, turned it off for awhile, and then turned it on again later to try watching again. Usually the first power on of the morning (from a cold start) seems to work every time. It almost sounds like, once the TV has had a chance to get hot from being used is when the problems begin to occur.

As of this writing, the TV seems to work fine, but I went ahead and took some voltages and everything seemed to be in order except for two connectors. One was on the Z-Sus board at the connector with the ribbon cable going to the Main Logic Control Board and the other was at the Y-Sus connector going to the Main Logic Control Board. Here are the voltages I measured and what they were supposed to be according to what is printed on the board:

[B][U]P101 Y-SUS Side[/U][/B]

[B]Expected readings:    |  Actual Reading[/B]

Pin 30: 15V               16.32
Pin 29: 15V               16.32
Pin 28: NC
Pin 27: 5V                 4.97
Pin 26. 5V                 4.97
Pin 25: 5V                 4.97

(the other pins had no visible expected reading to go by)

[B][U]P101 Z-SUS Side[/U][/B]

[B]Expected Readings     | Actual Reading[/B]

18V                    16.32
18V                    16.32
NC
5V                      5.02
5V                      5.02

(the other pins had no visible expected reading to go by)

So the Main Logic Control Board (PartNo: EAX64290701) comes between Z and Y SUS on the P101 connector and it's the only connector on all of the boards that had a reading other than what I expected to find. Am I right in thinking the Main Logic Control Board could be to blame for the sporadic no video?

Is there anything else I can check for?

As always, pics attached and thanks.