there is sound but there is no picture...this is not a permanent problem as sometimes it will go for a few days without any problems then all of a sudden the same fault will happen again

ian walsh, November 2011

The most likely fault is a poor solder joint on the power supply pcb.
Thats the board the mains lead connects to.
Otherwise an intermittent Diode or transistor on the power board.
Two OR three companies supply a repair kit for just this fault in Samsung TVs , Charles Hyde is one of them.

M Carter, December 2011

bad connection or dry joint on the y sustain board.

elec tech, November 2011