Recently my 3.5yo Panasonic TH-50PZ80BA decided to shut down, and indicate 7 LED blinks to me. It will power up for certain lengths of time, before shutting down. I've recently had the back off of it, dusted it down and tapped a few heatsinks, and currently it *seems* to be behaving itself...
However, as the back is off of it I'm able to hear a distinct buzzing from it when high levels of brightness are required. Both my wife and I can't locate the source, as it seems to be coming from all the SD, SU, SC, D, P and A boards! Is this to be expected, or indicative of a problem outside of the SC, SU or SD boards?
I was all set to start replacing the boards as per the service manual, but this got me thinking again... any information would be greatly appreciated!