Model: LN46D630 LN46D630M3F LN46D630M3FXZC

This TV would turn on and off with chimes but no backlight. Power supply is BN44-00463A. The PFC circuit generating 390VDC is suspect if the backlights don’t come on. I put alligator clips on the big capacitors and they were only reaching about 250VDC when the tv turned on before it shut down.

The usual suspects in this circuit are DP810, CI818, CP820, ICP801, CM809 and CM811. Electrolytic capacitors CM809 and CM811 were not bulged. I tested DP810 in circuit with my multimeter in diode mode. It measured open in one direction and 0.5V dropin the other so it was good. CI818 tested good in circuit with my multimeter in capacitance mode. CP820 didn’t test good and when I pulled it out, it tested as a resistor in my ESR meter. Value is 220pf/1KV and 2KV or 3KV can be substituted. With CP820 replaced, the backlights came on. If CP820 was not the fault, I would have replaced ICP801 which a FAN7930B IC.