Samsung PS50q97hd Flashing 5 Times

[buges]

I have the dreded sound no picture (turn it on led flashes 5 times) So far i have tested the VA & VS on the psu & they are correct. Vg on the psu is 14.5 (is that correct?) have removed upper & lower buffer boards & Y Main & X main Still nothing. If i just leave un801 (main board) connected to the psu i still get 5 flashes

The service manual says the psu should supply VS & VA voltages with only un801 (main board) connected but mine doesnt until i plug in either the x or y main. Led 5800 Is lit on the Y Main board.

The Psu is PSPF531801A (BN4400162A)

Thanks