samsung plasma tv no pic or sound

[GEFORCE]

Hi all.
My tv stopped working this morning.
Once plugged into mains the relay kicks in, on then off. Then when i switch on from tv the relay clicks then i get 4 led flashes on front of tv then nothing.
I found a service manual on the net and checked voltages.
Inside the tv the sticker indicates these voltages should be,

va= 70 vsc=-70, vs=175 ve=162 vset=173

but i get,
va= 70 vsc=-70, vs=33 ve=68 vset=55

Model no ps-42d4s
type no. ns42d4
Is this a power supply fault or x or y board.
Any tips on what to look for.
Thanks

[cadillacman]

Re: samsung plasma tv no pic or sound

a good first start is to visually look over EVERY electrolytic capacitor and see if any are bulged or vented.

[PlainBill]

Re: samsung plasma tv no pic or sound

If a visual inspection doesn't show any bulging caps, try unplugging the power cable to the Y sustain card and rechecking the voltages.

PlainBill

[GEFORCE]

Re: samsung plasma tv no pic or sound

Thanks for replys
There are no bulging or leaking caps, i also checked with an ESR meter but all seem ok, although most are in parrallel so there still could be one in there.
I unplugged the Y main board and got the followin voltages.

va= 70 vsc= -70 vs= 35 ve = 26 vset = 160 to 170

thanks

[PlainBill]

Re: samsung plasma tv no pic or sound

Strange. This looks like it could be a power supply problem. What happens if you also disconnect the Z-sustain?

PlainBill

[GEFORCE]

Re: samsung plasma tv no pic or sound

Thanks for reply PlainBill
I havent got the Samsung service manual for this set, but I found a Philips manual with PDP module s42sd-yd05 in it, which I am using.
I cant find a z sustain board so I am assuming you meant the x main board. I started from scratch and got the following.
all boards connected:
va= 70, vsc= -70, vs= 27, ve= 12, vset= 55 to 10.

y board disconnected:
va= 70, vsc= -70, vs= 33, ve= 18to 25, vset= 170.

x and y board disconnected:
va= 70, vsc= -70, vs= 38, ve= 156 to 12v, vset=172 to 164.

y board on x board disconnected:
va= 70, vsc= -70, vs= 35, ve= 160, vset= 56.

All fuses ok no dry joints. there is no schematic for this power supply Samsung BN96-01217A, if this is problem.

Thanks

[PlainBill]

Re: samsung plasma tv no pic or sound

Thanks for reply PlainBill
I havent got the Samsung service manual for this set, but I found a Philips manual with PDP module s42sd-yd05 in it, which I am using.
I cant find a z sustain board so I am assuming you meant the x main board. I started from scratch and got the following.
all boards connected:
va= 70, vsc= -70, vs= 27, ve= 12, vset= 55 to 10.

y board disconnected:
va= 70, vsc= -70, vs= 33, ve= 18to 25, vset= 170.

x and y board disconnected:
va= 70, vsc= -70, vs= 38, ve= 156 to 12v, vset=172 to 164.

y board on x board disconnected:
va= 70, vsc= -70, vs= 35, ve= 160, vset= 56.

All fuses ok no dry joints. there is no schematic for this power supply Samsung BN96-01217A, if this is problem.

Thanks

I'm inclined to suspect the power supply at this point. At $150 and up for a replacement repair is the only option. Good luck.

PlainBill

[GEFORCE]

Re: samsung plasma tv no pic or sound

Thanks plainbill
Im going to strip the board down and test the mosfet etc and see if i can find anything.

Regards

[attai003]

Re: samsung plasma tv no pic or sound

Please, can anyone help with the appropriate Volts and UF for the 4 big capacitors located upper front part of Samsung BN96-00249A (Power supplier board).

[olymbou]

Re: samsung plasma tv no pic or sound

the problem is the ml4824 i only had 70v and 5v stby