My Sony CRT TV Model KV-M1420U has developed a problem. After 15 minutes of perfect picture, the picture fades out by going through a colour change to purple then totally black. All channels are affected. Switching off for a few minutes recovers the picture but the situation repeats.
Anyone one got an idea where I should start to look for this thermal problem? I am trained and familiar with working with high voltage and electronic circuits but I'm not a T.V. engineer.
Beemer