Daewoo DT4242N Fault from cold

[briancampbell]

I have 3 Daewoo Plasma TV with the same fault.
At startup from standby the TV looks like it has an AGC overload type fault. ie Picture all distorted, Frame roll bad contrast. Sound seems to be ok.
After 30mins thereabouts the picture will settle down and will give an occasional jump and jitter through the day. I think its a fault on the power supply panel,

Has anybody seen or resolved this fault before.
Any help would be appreciated,

Brian Campbell