Samsung ps42c91h dyp 42w2 no picture does have sound

[Kennyzwiers]

Hello experts

I have a bit of a problem here. I have a samsung plasma that doesn't give any picture but does have sound.

I checked the voltage
Va 64 (correct)
Vs 5 v (should be 205)
Pulling y and or z board has no changing effect on volts. I think it's the psu.

I replaced the obvious bad caps. But that didn't change anything really. What should I test and or replace now?

What's the best methods to check for bad caps or diodes.
Hope to here from you guys.

Thanks in advanced.
Kenny

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

O and the led on the back blinks every second. That should indicate no errors right.

[niblettr]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

check the fuses. Check the big white rectangular resistors.

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

check the fuses. Check the big white rectangular resistors.

Fuses (om psu) are OK
What white rectangular resistors are you talking about.
Screens hot of psu added

[flocko]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

I think the first thing you need to do is to check the power board , to do this take all the plugs from the power board and leave just the mains connected(but not turned on as yet) . you will need a 470-1000 resistor on the bottom right connector you will see a pin that is marked PSon this you will need to put to ground (make low)and keep to ground turn on the mains you will hear the relay click , you can then check the small voltages on the board ( these should all be there as you have told us you think at is just the VS that is missing or low), but check these anyway. turn off the mains but leave PSon grounded . now find pin marked VSon , with the resistor connect between this pin and one of the 5v pins (The best way to do this is to use the plug that goes into the socket and unplug from other end as this saves soldering resistor in)when this is in place turn mains on relay will click and VS voltage should now show on the board as well , let us know what you get on these tests Flocko

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

Hello Flocko. Thanks for your reply. I did what you described and I got nothing on vs. Others like va do give the correct amount. (67). I have some low voltage testpoints and they were also correct.
Now I put in resistor like you said with the cable. Getting the 5v from the same pin row.
Any suggestions?

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

And there is 5v on the 5v pins

[flocko]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

So just to clear this with the resistor fitted between 5v and VSon pin and PSon to ground you have no VS voltage ? if this is the case your problem is with the Two biggest Fets (top )on the third H/sink from the left and the SMD diodes and resistor under the board you should check the soldering first, lots of bad joints with unleaded solder as it ages

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

Hello Flocko. Idd no vs voltage. Wich is abut weird cus I had 5vish there when it was all Connected.
You mean these 2 (see pic)? Is there a way to test these?
So far no loose connections

[Kennyzwiers]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

ALao a picture from the back. Maybe I am not seeing it. Could get a pointer on where to look on the back

[flocko]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

Parts to test are F801 Fuse ? most likely blown if QS801/2 are shorted but not all ways
QS801and QS802 test for shorts to all legs
DS803/DS804 diode test (some times hard to test still on the board if buying kit replace anyway)
RS812/RS814 check resistors are not open ,but show as value ?(in the kit so replace as with diodes )
replace ICS801 if QS801/2 need to be replaced
This is the common repair for no VS voltage ,all parts can be bought as a repair kit or on there own , internet search DYP-42W2 repair kit ,but make sure to get the right one there will be two the other being for low voltages side (small FETs )

[CAIIIA]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

Hi, Kennyzwiers! Try repair this SMPS with schematic. Hi, forum! Among the frequent breakdowns in these PSUs is very chip MS33067. Chips in the power supply unit 2, so you can swap them. Also be sure to taste it to replace both the condenser to the new oval circled column in the diagram line. The rest should help scheme. Good luck!

[Matejic]

Re: Samsung ps42c91h dyp 42w2 no picture does have sound

Hi to all.
I have the some problem with that TV (ps42c91h dyp 42w2 no picture does have sound).
I have all voltages accept Vs. I don't have any voltage on Vs.
QS801 and QS802 transistors are OK.
DS803 and DS804 diodes are OK.
RS812 and RS814 resistors are OK.
Fuses are OK.
I any chance to be the ICS801 (MC33067)?

Thanks in advance.