Samsung plasma ps-42d4sk

[tupon79]

I have been given one of these sets with sound no picture. Can anybody help with a schematic of the power supply BN96-01217A. I do have a service manual for the set, but I guess Samsung does not want the power supply to be serviced, as there is no circuit of the SMPS. I have ascertained that I am missing VE, VSET and VS rails but it would be much easier to fault find if I had a circuit and PLEASE HELP ME WHAT IS BROKEN..

[PowerAmpFreak]

Re: Samsung plasma ps-42d4sk

Are you sure the powersupply is the problem?
Search for the service manual for the PANEL and not the TV modell.
Generally there are two different service manuals. One for the tv modell which covers generally the mainboard (inputs etc). The panel service manual might contain a lot more like plasma driver boards, powersupply, troubleshooting, etc
There are no flashing leds on the powersupply board? Or perhaps a red led continously on? This might indicate protectmode has kicked in which could be the result of a driver board shorting out one of Va or Vs.

[tupon79]

Re: Samsung plasma ps-42d4sk

Hi,PowerAmpFreak
in the power supply there is no LED for indication, I have checked all the voltage needed for mainboard, logic board, and Buffer. All voltage Normal, except VSET, VE and VS .. if ever can the same problem please help .... thanks

[PowerAmpFreak]

Re: Samsung plasma ps-42d4sk

Disconnect loads on VS, VE and Vset and start up the psu. Constantly measure for example VS during start-up, there might be a short period the voltages is up, then "something" sense abnormality and shutdown these voltages again, to limit damage elsewhere.
Did you search for the PANEL servicemanual yet?

[tupon79]

Re: Samsung plasma ps-42d4sk

PowerAmpFreak:
I've tried like you are referring to, the results still nothing came out voltage VSET, VE and VS.
I have yet to get service manual

[PowerAmpFreak]

Re: Samsung plasma ps-42d4sk

Check PDP modell and search for this in Elektrotanya.com
But first, are you familiar with powersupply troubleshooting?
Do you have some knowhow about SMPS?
A powersupply could be very dangerous to work on, if you don't know what you're doing, especially the primary part of the supply.
Are you sure the PFC frontend works ok, giving 380-400VDC on the big "input" caps?
It appears to me one of the smps is running ok, powering low voltages to mainboard, audioamp and auxilliary supplies.
Your problems seems to be the "big" smps giving the high powers and voltages to driver boards. These supplies use to be halfbridges in different configurations.
Could you take some good pictures of the powersupply and I will take a look.

[PlainBill]

Re: Samsung plasma ps-42d4sk

That set uses the S42SD panel.

If the problem is the power supply, not the Y-Sustain it's going to be interesting to troubleshoot.

As always, first determine if it IS the power supply oo one of the Sustain cards.

PlainBill

[scokljat]

Re: Samsung plasma ps-42d4sk

I'm quite interested on the outcome of this one as I have exactly the same problem with same PSU. All voltage Normal, except VSET, VE and VS... No change when YSUS and/or ZSUS are disconnected...

My recent original post:
https://www.badcaps.net/forum/showth...ht=BN96-01217A

Cheers,

Suad