I haven't done anything yet. NOBODY from this forum answered except you. So I looked for other forums and found one called Fix-it Ya. Here is what they say, and I probably will try their suggestions soon.
The problem could most likely be with the set's STK ICs. The soldering comes loose, sometimes actually coming loose INSIDE the IC, where it solders in there! Heat/cold over and over translates into expand/contract over and over.
Just resoldering the legs usually does the trick, but if you have continued to use your set while hurt, the ICs may eventually go out completely and need replacement. Resoldering them in before that time usually saves the ICs and never needs to be done again.
I then asked what do theylook like and here is the response:
There will be either one or two of them, and they will be heavily heat sunk - as in mounted on a big heat sink, with vertical fins. That's all I can say without seeing the unit in front of me, open. They usually face towards the front, are in the middle of the middle board, and the name of the ICs is covered by a screw-on plate, which has to be removed for replacement.
Be generous with the heat sink compound when replacing the ICs, get the old stuff off the heat sink with a putty knife if it has dried out.
To check whether you need to replace the ICs or not, with the unit on if you tap on the heat sink with something long and not conductive, like a stick, and it affects your conv - be VERY careful, this has to be done while the unit is on - you can probably get by with just resoldering the legs. If not and it just won't converge, IC replacement will be necessary. I recommend replacing both if you replace one, because next week the other one may go out and you may have to get in and out of the unit all over again.
Best way is usually to remove the entire light box, tho sometimes it's best to remove just the board, other times you can prop the whole board up and do the resoldering on your back.
The name of the STK ICs is STK392-570. You can Go to a website "bluestar-online.com" and find them for sale.
Hope this helps. It sure would have been nice if other people replied.