LG60PB690 60" plasma half a picture.

[clark97]

Got an LG 60PB690 in for repair. Was sound with no picture. Replaced the top buffer and screen comes up with a display in the top half and bottom half blank.
Ordered a new bottom buffer thinking mine to be faulty but exactly the same fault with new buffer.

I've never seen it before but has anyone had a faulty ysus board cause this problem ?

Thanks in advance guys