Television and Home Theater

helloo i have a zenith P42W22B,and when i turn it on the picture will stay for 5 mins then it start to go crazy for a min,then it turn to black after that and it will say no video signal on the screen ,then i power of and leave it for like 20mins then ill turn it on and the same thing will happend i have the picture 4 like 5mins then the same story.......plzz advice me

thank you

An older 50" crt Zenith rear projector.

 Menu only allows moving red and blue centerpoints. No external way to adjust rotation of the guns, focus, or image scale.

My red and blue guns are very slightly out of rotation w the green, but I can live with that. My problem is that my red gun has intermittent problems with reduced image height. Can adjust center, but at extreme top and bottom of image, the red is a half inch "short". Vertical scale is the main issue, as horizontal doesn't appear to be off, or at least not much.

I need part #313917752971 and #313912443421 for my Philips 17PF9945/37 Flat TV and can't find it. I spoke with Philips direct and was told that they no longer carry those parts. Can you help me locate these parts?