I have a Panasonic Plasma TV, model TC-P60U50. I purchased this in 2012 brand new. It worked fine until about the last month or two, at which time you could turn it on, be watching it for a while, and then all of a sudden it would shut off, showing 7 blink code. Turn it on again, watch for a while, then turn off. Never fully died. Every time it did shut off though, 7 blinks, and the time lapse of when it would shut off would be different every time. From the internet and the service manual, I pinpointed the problem with one of the buffer boards (SC, SU, SD) board. I ordered 3 boards from a parts supplier on the internet. They get parts from tv's that have cracked screns, but the parts are tested and guaranteed to work. After installing all parts there was no more 7 blink code, but I did get a garbled image on the screen with clear sound. Closer inspection of the SC board, I noticed that there was a TP1 fuse missing, hence probably why the garbled display (very pixelated). Sent board back. Received a replacement SC board. Installed in tv, and this time, back to a 7 blink code. No display whatsoever. Unconnected power supply cable to SC board, got 8 blink code. Re-hooked SC board, 7 blinks. Seems to me it's almost impossible to get two bad SC boards in a row, wouldn't you think? Should I look at replacing the power supply board, SS/SS2 boards? That is the only two other boards that I believe can be the cause of the problem. Don't think it's the A board (main video board) but I could be wrong. If Panasonic says that the 7 blinks is either SC, SU,SD, then could it really be another board? Never had an issue with the picture/panel, no buzzing sounds, etc. Thanks very much for your help.
It's hard to say.
I suggest you try the buffer board replacement.
Based on your symptoms and explanation, the buffer board may be the trouble maker. It can cause pixelation problems, I think.