samsung y-sus repair assistance please!unusual voltages.

[zookeepertoo]

hi, on my y-sus board 3 of the 4 mosfets (748228) have blown. I have removed all 4 and am now looking for other defective parts on the board. Strangely the area surrounding the mosfets when the board is powered up shows predominantly a - (negative) 192v and in a few places -(negative) 67v. This includes the tops of the capacitors around that area of the board. Has anybody any idea which other components to look at to find the faults now please. many thanks for looking Dave.

PS50C96HDX

850HW-YB02

LJ41-05120A
REV: 1.3