Dead Samsung Plasma PS-42C7HD No Standby

[london-freddie]

Needing help again please
Just got this dead tv given and want to try and save it from scrap
Had a quick look at it this evening
No power, dead no standby light
Took back off, fuses check ok no 5v on power board to standby, all caps visually look ok.
where do i start testing from now any help appreciated
power board is BN96-03743A DYP-42V5

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

power board pic

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

there seems to be no output voltages at all coming off this power board

[ReeceyBurger123]

Re: Dead Samsung Plasma PS-42C7HD No Standby

Checked fuses on Psu ?

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

hi found 4 fuses on power board all are ok

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

just checked 5v standby pin on powerboard and I have continuity between 5v standby output pin and ground, in fact several voltage pins seem to go to ground, am i right in thinking short somewhere on board

[tw2005]

Re: Dead Samsung Plasma PS-42C7HD No Standby

Just looking at Ohm supplies kit, for 5V standby.
FAULT SYMPTOM:

+5V STBY CCTS FAULTY, DEFORMED CAPACITORS AND STUCK IN STBY

They list CS04
CM422
CM408
CM421
C5051
C5065
C8052

and they have some others for Dead TV, QA801 or QA802 S/C

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

on these kits what does CCTS stand for

[tw2005]

Re: Dead Samsung Plasma PS-42C7HD No Standby

on these kits what does CCTS stand for

plural of cct, circuits

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

ok checking powerboard now this is what i have got so far
No AC at rectifier
No voltage in 2 big caps
cant find where i am loosing the ac

[vinceroger69]

Re: Dead Samsung Plasma PS-42C7HD No Standby

did you check the barell type fuse just too the right of the white one also can you upload pictures of the bottom of the power supply thanks.

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

yes that fuse checks out ok, will get a picture of bottom of board asap

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

back of board

[budm]

Re: Dead Samsung Plasma PS-42C7HD No Standby

back of board

That is good pictures of the bottom side of the board, can you please retake the pictures of the whole top side of the board again for me? The one you post was not quite focused well, thanks.

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

thanks will do it now

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

hope these are better

[budm]

Re: Dead Samsung Plasma PS-42C7HD No Standby

OK, you are not going to get AC to the bridge rectifier until the main board sends the PS-ON to turn on those two power relays to supply the AC to the bridge.
You need to check the fuse for the STBY POWER SUPPLY as marked and check to see if you do have 330VDC between the two legs of the main filter cap for the STBY power supply to run the STBY SMPS IC or not.

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

hi
ok thanks for that checked that fuse, it is ok
No voltage at that filter cap for the STBY power supply

[london-freddie]

Re: Dead Samsung Plasma PS-42C7HD No Standby

i am confused now, you ask me to check for 330VDC between the legs of the main filter cap as marked,, which there is not any voltage
however i thought i would not get any DC volts on the board until the AC had passed through the bridge rectifier, or am i thinking stupid

[budm]

Re: Dead Samsung Plasma PS-42C7HD No Standby

OK, check the resistance between
Point A and B
Point B and C
Point D and E
Point E and F

Check the two rectifier diodes, check the NTC (should be <10 Ohms or so)