Originally Posted by PhilipsPhanatic CONFIRMED
: Went dark and the tap fixed it again.....now I just have to decide on what to do. You say that re-seating the driver boards (you mean, re-bolting them ???) fixed the problem but I am surprised a board can get loose in the first place. A wire or connector or fuse or capacitor I could see. Any idea how a board gets loose when the TV hasn't moved an inch in 3 years ???
My theory has been talked about if you follow the link path I referred to. The re-seating procedure is also discussed in the article and the ones it links to.
One possibility is the defective connector theory. They build up contamination, and the connection deteriorates. Re-seating temporarily cleans off the contamination and buys some time.
Another possibility that has occurred to me may be the way the boards are mounted. The mother board and the driver boards are screwed into stand-offs installed in a panel. If the boards and the panel do not have identical thermal expansion characteristics, which is not unlikely, the connectors between the driver boards and the mother boards will be stressed over time as the TV heats and cools. My Plasma TV definitely warms up quite a bit. During heating or cooling, the boards may shrink, compared to the panel, which would separate the connectors. When they grow with respect to the panel, they should get pressed together again, but I have no idea, if the insertion and extraction force requirements for the connectors are an exact match. Over hundreds of temperature cycles, the connectors may be walking out of their ideal seating area. Actually, I don't consider the mounting arrangement to be a good one. They probably should have made it possible for the driver boards to slide(The holes in the boards could have been slotted and they could have used mounting screws that did not bind the boards to the standoffs, or the boards could have slid into a track), or they could have used a flexible connector arrangement.
Obviously, I don't have the information to be sure what is happening, but a temporary repair for both of these possibilities is the same. The re-seating procedure I have performed included removing the screws and unplugging the driver boards and plugging them back in again. The screws were then re-installed. The process would tend to clean up any build up on the surface of the connectors, undo any separation of the connectors that might have taken place, and take off stress that may have built up in the board mounting system.
It is a fair amount of work to do the re-seating, and you should follow ESD procedures, but torx screw drivers are the most unusual tools needed although an ESD wrist strap is a good thing to have. I have posted what I went through. It is up to you whether the effort is worth it to you.