Television and Home Theater

My friend has a 42" samsung plasma thatone day stopped displaying anything.  He said that while he was watching he heard some crackling and popping coming from the set and then the screen went out.  He can still hear the audio from what he is watching but gets no video display at all, meaning there is no volume bar or on screen menu.  Any help in figuring this out will be appreciated.

Tom

Set has a good picture except for squiggly lines on the edge of images on the screen. I am a certified electronic tech and could really use a schematic. Any help would be appreciated.

 Thanks,

Kenny

Hello, I am hoping that someone will be able to help me a little.  My tv plays and sometimes the tv blinks blue and then the screen will turn completely blue and then the tv will shut itself off.  This does not happen all the time, but i would like to fix this as the tv is very nice and works fine other than this issue.