Samsung PN50A450P1D Plasma - Audio No Video

[snowman0269]

All the Vs, Va, Ve, and Vsc voltages are correct via the test points on the boards. I've found the service manual for my TV (and I can attach it if requested), and went through all the troubleshooting steps listed in there (flow charts, voltages, etc). An internet search for Samsung plasma troubleshooting led me to the following video: https://www.youtube.com/watch?v=JjrwTZC5nVg

Test patterns never showed. The only thing I could get to show on the TV was a blinking red pixel when I connected a tablet via HDMI. Picture is bad, but I tried multiple times

All the fuses, even the soldered ones, test good. No bulging capacitors are present. On the logic board, the LED blinks about once every second (which I'm led to believe means the Xmain, and Ymain are good), so I'm thoroughly lost on this TV. I've also tried to scan for shorted buffer chips on Ymain (it's the Ysus and Ybuffer I think), by doing diode short test with ground, and all 6 buffers, both sides. No beeps. LED 2 is blinking on the logic board, but LED 1 is not.

If there is something I'm missing, please tell me so I can do it.

Thank you,
Matthew

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Apologies, I missed a few pictures to upload. Here are the rest. And a quick note on this TV. To get the test patterns, you not only have to short PS_ON and ground, but also VS_ON and Standby 5V. Then short pins 3 and 4 on the test jig.

Thank you,
Matthew

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

So are you able to get test patterns?

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Test patterns never show other than that blinking LED. TV looks like it's off other than that.

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video



This image here looks like a faulty control board.

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

That's the picture of the LED on the front of the TV. Is the control board the logic board? Or am I calling it wrong?

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Yes control board = logic board.

Can you find vsch test point on the y-sus?

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

The point I tested on the y-sus was labeled "VSCAN." Is that the correct one?

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Yeah from your earlier post you said vscan was accurate.

But is there a vsch? Your picture of the y-sus isn't great.

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Mine looks almost exactly like the one in this ebay listing. The VSCAN point wasn't big like the others, however. It just looked like a soldered point, with nothing attached. But still had the correct voltage.

http://www.ebay.com/itm/Y-SUS-BOARD-...3D261643992194

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Oops. Just saw your post. Lemme go look for vsch.

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Also check your getting VA voltage here.
And check each end of this fuse for voltage.

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

No vsch, but vscan had two more test points. One reading -45 to -50 and the other reading 5.2. What side of my picture is that picture you posted? By the way, love your Heisenberg. Did you draw that?

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Oh, I see where it is. Which of those two cables puts out VA?

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Fuse is good, VA voltage (56V) is good here too.

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Ok well those vscan voltages are out.
Can you post a picture of where you're measuring them?

Lol the Heisenberg pic was just found randomly online.

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

By the way, the first time I tried reading those VA voltages down there, I put my multimeter lead on the right side, and accidentally grounded one of those pins by the metal. Fuse and VA still test well when I tested on the green board. All my voltages still good. Did I mess something up?

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

The capital letters VSCAN, the top one gave me the -195, the bottom one gave me the -45 to -50. The "Vscan" gave me the 5.2. And these points are between the big green caps and the heatsink on the right side of my Ymain board picture.

[Hamie]

Re: Samsung PN50A450P1D Plasma - Audio No Video

The small Vscan is just to mark the potentiometer.
Your VSCAN is fine.

If you unplug the zsus do you an image.

(Zsus = Xmain)

[snowman0269]

Re: Samsung PN50A450P1D Plasma - Audio No Video

Is Zsus the one with the VE voltage? It's on the opposite side of the TV.