Protron 32 inch HDTV

TV randomly changes its source from component2 to AVI (bringing forth the blue screen of death! Obviously the TV says "no input" once the source is changed). I have taken batteries out of the tv remote and cable remotes to eliminate possibility that the cause is a random signal from one of the remotes. We thought it may change due to overheating at first, but AC has been on and sometimes this occurs when the TV has not been on long. Happens randomly, TV may be ok for hours or even days at a time, then it will do it 2 or 3 times in an hour. Any help would be appreciated.