Samsung plasma PS51D6900 repair , help needed

[Chrissygizmo]

Hello to everyone, i am new here so I apologise if I've put this in the wrong section or something.

I have a Samsung PS51D6900, Power supply Board model PSPF371501A. It has standby light but no power. Sometimes when I turn it on the screen will flash on for a split second so I have dismissed the backlights - (just my opinion, I might be wrong because I'm just a novice watching YouTube videos and trying my hand at this).
There is no 5v power from the supply board either.

Thanks

Chrissygizmo