Power board for jvc hd52g886

I replaced the board with oem from jvc,and it has the same part#,So i took the power bourd out and tested the boards side by side and everything tested ok,but i am limited with out a scope.I was hopping that some one hade these problems and had some info on how to fix it,if you have any new help please send it to me i would most thankful.

You can try removing the 3wire plug that runs to the ATSC tuner (1orange wire 2 white wires). This will tell you if the tuner is causing the shutdown. This is a common problem.