I found a GE Porta Color!

[DaveWM]

well it maybe the problem, I have found that if you just use them they often get better. I just picked up another made in 1975, it seems to be working fine, the biggest issue is often dirty controls, but again use will often fix that as well.

One thing about tubes, often new ones are bad so its always a good idea to at least test a new tube for shorts before using it.