Samsung UN65H7100AF Dead No Power

Model UN65H7100 UN65H7100AF UN65H7100AFXZA

The owner indicated he heard a pop and the TV died. He also found the main fuse blown. The power supply part number is BN44-00717A. Blown fuses typically are caused by shorted diodes and FETS and I found a short in one of the two PFC switching FETs 60R360 (NCH, 600V, 9A). I replaced both QP801C and QP802C with IPAN50R500 (NCH, 500V, 11A). The PFC circuit runs at 400V and the main filter caps are only rated to 450V so the lower voltage should be ok.

With the FET and fuse replaced, the TV powered up. I did recommend to the owner to not run in Dynamic mode since it could burn out the backlights.

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