Television and Home Theater

I have replaced conv ic's a while back. No problems for a few months then one day tv said powering off in x amount of minutes. Like the timer had been set. Wife was watching tv when this happened. After that it has never turned on since. It will show the blinking light 3 times when I plug in the cord Indicating the processor is good and will show a diagnostic code of 12 indicating no problem when accessing the diagnostics from the front panel. Any ideas?

I am wondering if anyone has installed a smaller muffin fan on or near there IC heat sink? I just replaced the IC on my Mitsubishi WS-55711 and it seems to me that the heat sink is really hot. I used an infrared thermometer to check it and it reads about 125 deg. Is this normal or should I be nervous. I made sure the chip was covered with heat sink compound before I secured everything down. Any tips or thoughts would be appreciated.

Thanks

I have a crack in the Rt upper screen of my Sony KP-51WS510 tv. The picture still works great but is this repairable?  If so what could the cost be? Can you still purchase these sets? I bought mine in 2004.