Bad BN44-0809A power supply board.

[helloman]

I started troubleshooting the samsung 75inch tv board, that died suddenly one day. I disconnected the power supply board and noticed that the fuse is blown. Replaced the fuse and new fuse is blown immediately. Any next steps to troubleshoot?

The board is BN44-00809A

Is there a schematic for the board? I read online that rectifiers might be bad, How to check if the rectifiers are good?

[bscottjohnston]

I am working a similar problem on an 80" Sharp set. The fine folks here recommended I build a dim bulb tester to avoid blowing fuses. The schematic might be on the back of the power supply believe it or not.

[bscottjohnston]

This YouTube is pretty good. I'm learning a ton tonight. One thing I am noticing, since I have a shorted MOV near the positive lead of both of my bridge rectifiers, they appear to be wasted. You might have to desolder them to test them correctly outside the circuit.

https://www.youtube.com/watch?v=K-oNaQvMQco