Plasma tv problem

[jacko1970s]

Hi got a Panasonic th-p42x10a plasma tv red light flash no picture traced the x-sus board was shorted two transistor bad so ordered some but also seen same board on ebay for £4 so bought it. Fitted board screen comes on then after some time could be 30sec 3 mins etc then goes off.All caps look good on power supply board so a bit stuck now as to what to look for any help appreciated.
Got a short video of it on then going off but can’t upload here
Thanks
Jason