My samsung 50 inch tele when switched on has sound but no picture the television is jst over a year old

What is your TV - plasma or LCD?
Plasma: Both Y-boards and buffers has the same problem -no picture when it was defected. Sometime X-board does it, too.
LCD: If you see picture moving on the dark screen. The inverter problem as it has no swicth on back light.
If back light on, T-con has problem.