Re: Samsung UE40D5000 power board - 9.4V on B13V


I measured across CP803S because that should be the same voltage right? I get 320VDC both with and without PS-ON shorted to A5V.

Would that indicate something to be wrong on the hot side? I'm surprised the A5V is exactly 5V then tho.


I might not have the correct voltage on PFC out, see above!


I'm not sure where to probe for this; see attached images.

Thanks so much already ...

I'm strugling today with trying to fix a UE40D5000 power board.

A5V gives a nice 5V, B5V and B13V stay off until I short A5V to PS-ON, so far so good.

B5V comes up as a nice 5V as well but B13V gets me 9.4V max.

Also backlight doesn't get power, those pins stay at 0 even if I put 5V on BLU_ON (measuring across CH1+ and CH1- on CNL802).

After turning on PS-ON, I see about 165VAC going into TM801S; I'm not sure what voltage I should see there.

The caps next to CNL802 get 96VDC, which seems too low as well since CNL802 should be 268V....

Re: New Members - please post your introductions here

Hi all,

Studied electronics in the past and always tinkering around with stuff.
Thanks to this community and their great information I've been succesful for years :P but finally time to participate / ask questions as well.