I just picked up this CRT listed on Craigslist, and after a tiring and not so gentle transport, plugged it in to find that every 5 or so minutes, the picture will take a shade of green within a second. It stays that way for maybe 5 to 15 seconds, then returns to a neutral, natural color. I happen to have decided to watch an old black and white movie, and it's very clearly doing this, but also I think it may shift slightly red some of the time, but I'm not sure if that's just my eyes adjusted to the slight green when returning to white... I think that might very well be the case though because I only think I see the red some of the time, and never quite looking the same.
It's a shame this is happening because when it returns to normal, it looks surprisingly great. The black and white movie looks so purely black and white... Then suddenly it shifts slight green and it is so clearly spoiling the viewing. Otherwise, you don't really notice it too much when playing a video game.
Another thing is that when I first realized this was happening, I noticed that when it shifted back to normal, I thought I could hear that usual CRT prickling static sound - maybe degaussing?
The guy I got it from said it was working fine and seemed helpful, so I don't know if he just omitted this issue or if it was caused by the rough transport. I can't really find any explanation or solution searching online with general, vague descriptions of what's happening. I opened up the back of the TV to see if there was anything obvious, but all I've really found is a pretty dusty interior that I intend to blow clean with some canned air later today.
I'm really hoping someone knows what this could be, and even better, knows a solution that I could hopefully do myself.