Television and Home Theater

turn on tv ok for about 5 or 6 hours then turns off and trys to turn back on. light turns on and off. then i turn off for about 10 to 15 min comes back on some times will only stay on a few min then off or will stay on for 1 to 2 hours. any one that could help thanks al reed

I just started having a problem with the vertical on a 27" Zenith. When I first turn it on, everything is fine. After a minute or two, the top and the bottom of the screen will flutter, then the picture will compress to about 5" wide across the middle of the screen. At the bottom of the 5" bar there is a very bright 1/2" line. If I tilt the whole set on it's base the full picture comes back, or if I tap it on the side it will come back, but then right away it revert's back to the 5" screen. The model # is SR2765S, manufactured in 1996.

My 15 year old Sony KV27EXR10 Trinitron TV keeps going from good color picture to black and white then audio crackles with  noise in picture and then it goes back to color picture again, and it does this cycle over and over and over every few seconds.  When it first happened two days ago, it took 5 minutes after I turned the set on for this problem to begin, but now it just does it right away and over and over and over. Doesn't matter if I use tuner in set or in VCR, play a tape, or what channel I pick. Any suggestions?