Weird Sony KV-27XR

The TV had a burnt connection on the line-trafo, I fixed it. Now it powers
up nicely. But after a few minutes screen goes black or picture starts
rolling, green channel nr (OSD-text) also jumps... This last for a little
while then it's fine again, sometimes for a long time, other times for a
minute or two before the same problem is back...The TV also gets very
"static", a lot of crackling sounds when I turn it off ( a little less when
turn on). Too much to be normal, I suppose..

Anybody got some hint or tips? I'm most familiar with repairing panasonic
tv's, but this shouldn't be too diffrent...I hope..

Thanks in advance
Stig