Samsung PN64D7000 No Power

[Durangee]

Hello all, new to forum and have already gained quite a bit of knowledge today but need a little more.

The TV simply died while watching and will not turn back on. When the TV is first plugged in, the power light will blink 6 times but that's it.

Reading a previous thread with a similar problem and similar model Samsung, it was stated that there should be 3-5v on the "PS-ON" pin. That voltage is not present when all boards are connected. However, I can disconnect the cable going from the logic control board to the Y-Sustain board and the voltage returns reading 3.2v. I can press the power button and the power light stays on and the voltage is 3.2v, i can press it again, the light goes out and the voltage drops to zero. Does this point to a possible bad Y-Sustain board that's shutting down that voltage when connected??

I've attached a couple of pictures, the first showing all boards connected, and the second showing the cable that I disconnected to get the PS-ON voltage back.

Thanks in advance....great board!!

[tom66]

Re: Samsung PN64D7000 No Power

Nice massive TV there.

You can isolate if it is a sustain board problem.

Unplug TV for 1 minute. Then, disconnect power and control cable for left hand board (looking from back.) This is your Ysus.

Plug TV back in - don't expect a picture but you might get different behaviour.

Now repeat with right hand board and see if it powers up, this is your Zsus. With a disconnected Zsus you may get a poor picture (faint, sometimes purple-tinted) but not always, but does power LED behaviour change?

[Durangee]

Re: Samsung PN64D7000 No Power

Thanks for the response tom.

I did as you suggested above but the only time I can get the TV to change how it responds is when the ribbon cable in the second picture is disconnected from the ysus.

When the boards are disconnected as you suggested, i still get six blinks when the TV is first plugged back in. When the ribbon cable is disconnected the red power light stays on and will turn on and off with the power button, but I have no other TV function.

[tom66]

Re: Samsung PN64D7000 No Power

That does seem to indicate a Ysus problem. You can check for shorts with a meter. Post a close up pic of the power connector going to Ysus.

I had a Panasonic plasma which would still shut down with the power disconnected from Ysus: it was looking for a signal over the control cable.

[Durangee]

Re: Samsung PN64D7000 No Power

The plug on the left is direct from the power supply. The plug to the right goes directly to the xsus.

[tom66]

Re: Samsung PN64D7000 No Power

Okay, check the voltage across C5045 or its neighbours. Be careful not to short it out (which will make a nice bang, but shouldn't damage anything.)

[Durangee]

Re: Samsung PN64D7000 No Power

When the TV is first plugged in the voltage reads above 200v dc but quickly drops to about 20v and then slowly continues to below 10v

[tom66]

Re: Samsung PN64D7000 No Power

When the TV is first plugged in the voltage reads above 200v dc but quickly drops to about 20v and then slowly continues to below 10v

That probably indicates the lack of a short circuit condition. It would seem like there is still a Y-sustain problem. Try disconnecting the upper buffer board, connected to the Y-sustain. If the problem still occurs, replace the upper board and repeat with the lower board. (With one board removed you'll usually get half a picture.)

[noahc72]

Re: Samsung PN64D7000 No Power

Any progress on this TV? I have a similar TV but different problem(s).

Does yours have any LEDs on the logic control board?

[Durangee]

Re: Samsung PN64D7000 No Power

That probably indicates the lack of a short circuit condition. It would seem like there is still a Y-sustain problem. Try disconnecting the upper buffer board, connected to the Y-sustain. If the problem still occurs, replace the upper board and repeat with the lower board. (With one board removed you'll usually get half a picture.)

Sorry tom, been away for memorial day. I tried what you suggested but no change with either board disconnected....still 6 blinks when first plugged back in. Only change is when the cable from the logic control board is diconnected.

[Durangee]

Re: Samsung PN64D7000 No Power

Any progress on this TV? I have a similar TV but different problem(s).

Does yours have any LEDs on the logic control board?

I think my issue is being narrowed down to the y sustain. Yes, the logic control board has one green LED that blinks about once every couple of seconds.

[Durangee]

Re: Samsung PN64D7000 No Power

Update....

Received a new ysus board today and just installed it. It worked!
TV is powering up and all functions seem to be back to normal.

Thanks for all the help in tracking this down guys. Much appreciated.

I've got a pesky little vizio that wont power up so i'm sure i'll be back.

[tom66]

Re: Samsung PN64D7000 No Power

An interesting problem certainly. I've noticed quite a lot of Samsung plasma TVs with sustain board failures but mostly on the X-main which causes a dim/slow picture. Thanks for posting your fix and enjoy your TV.

[alika808]

Re: Samsung PN64D7000 No Power

Update....

Received a new ysus board today and just installed it. It worked!
TV is powering up and all functions seem to be back to normal.

Thanks for all the help in tracking this down guys. Much appreciated.

I've got a pesky little vizio that wont power up so i'm sure i'll be back.

Hey Durangee, this an old thread but I am wondering where you bought the parts. I think I have the same symptoms with my TV. Thank you.

[alika808]

Re: Samsung PN64D7000 No Power

Disregard the previous request. I found this site for the parts.

http://www.encompassparts.com/