Vizio VP50HDTV20A black screen

[sigmanuh1457]

Hello, I just wanted to go ahead and say that for last 24 hours I have searched and searched for a solution to my issue but with no luck. I really got in over head and screwed things up. A friend of mine has the exact same tv as mine. Same model number about same build date (i believe they are one month apart). But his screen started having about 5 to 10 vertical pinkish one pixel lines. I told him I could help him check out and see if we could figure out what is going wrong...I took my perfectly working tv and tried help troubleshoot his tv by swapping boards from mine to his. Needless to say I now have two non-working tv's.

I guess lets trouble shot these one at a time now so we don't get confused between the two. It used to have 5 to 10 vertical pink lines and that was it. Would have great picture other wise and perfect sound. Now, after doing board swapping I have nothing.

As soon as I opened up the tv I noticed I had some bad caps on the powerboard. Puffy and leaking a little. So, I figured I could just swap power boards and everything would work fine. After swapping the powerboards, the tv still had those vertical lines. Then, I decided to swap the video driver control board. And still same issue. Next, I swapped the X Main board, still same issue. Then, I swapped the Y main board, still same vertical lines. Then, I swapped the main board, still same issue.

Finally, I just went ahead and took the set all apart down to chassis. And made sure ever part from my working tv was in the tv with the pink vertical lines. After putting it all back together, I fired it up and NOW I just get the click and black screen. So, now i have made my issue worse. I have no video at all now.

I tested the VA and VS volts on the power board and they are within spec. of what is listed on the powerboard. But they only have power output for about 7 seconds and then stop and shutdown.

I really at a loss of what to do or how to go about testing this... Im handy with fluke meter. Just please tell me what to test or what direction to go in troubleshooting... Also, the tv is back to it originally state as when I started with all its original parts in it and not powering up with a black screen.

Vizio
VP50HDTV20A
Dec. 2007 (build date)
part # 10143050022 (on back of tv above serial and build date)

screen = PDP50X4TA35
powerbaord = AAX30284301 REV. 1.0
mainboard = 3850-01220-0150 (2A)
control board = EAX370802201
x main = EAX34042701
y main = EAX34042601
upper (y sus) = EAX37107601
lower (y sus) = EAX37107801
buffer boards = (cant see part # right now)
audio board - 0171-2871-0241

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Anyone with some direction of where start testing?

[drpj23]

Re: Vizio VP50HDTV20A black screen

So, let me get this straight, all the parts from the working (your) tv are in the broken or pink line (friends) tv. Right?
Ok, although this is simple, it helps to not overlook it:
First make sure every connection is seated properly or even connected and in the right slot.
Second, is the p/s just clicking off after you turn it on or upon plug in?
And what does the power light do (i.e. is it orange (or whatever color) originally then green and stay green when relay clicks or goes back to orange?)
My vizio may be doing something similar too, but am stuck on it, and still working on it.

[selldoor]

Re: Vizio VP50HDTV20A black screen

"So, let me get this straight, all the parts from the working (your) tv are in the broken or pink line (friends) tv. Right?"

WRONG - he says: Also, the tv is back to it originally state as when I started with all its original parts in it and not powering up with a black screen.

However I agree - connections check especially the ones to the panel

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

The tv is back with its original parts and now will not display anything. I have checked connection multiple times yesterday and today. I am considering taking it all back apart and looking over it again.

The orange light comes on when plugged in... When I press power it turns to green and stays green until I turn it off.

[cashkennedy]

Re: Vizio VP50HDTV20A black screen

The original state was with pink lines, now it is in a worse state where it wont turn on / stay on.

I dont have any experience with plasmas, but i know they have a lot of settings that are programed at the factory to compensate for variances in screens. Not sure if you can just swap boards infinitely like that on a plasma. Though i think it would work, just not display a great picture.

You might have a part/wire/board grounded accidentally causing it to fail its self check when it is first turned on. Do you have all the boards/wires in the proper place and fully screwed down, not just placed approximately where they go.

[drpj23]

Re: Vizio VP50HDTV20A black screen

Sorry, Sorry, I was doing something while reading it must have not finished it lol.

Anyways, hmm, you could always disconnect both Z sus and Y sus and see if that is tripping it.

Generally, you can disconnect board and try to single out the "problem board" per se but dont leave the tv on for more than 30seconds with anything disconnected.

I would be interested to see what happens if you just switched the power supply again.

But, in agreeance with cashkennedy, make sure they are screwed down since some screws act as the board's ground.

Lastly, check the fuses, they are usually on the Z and Y sus board by the main power wires (the thicker ones) from the power supply. They may be ceramic type (white) so a continuity tester would be very helpful. And there are also surface mount type fuses they are also white with gold or silver tips, kinda looks like a bigger surface mount ceramic cap. Check those on the Z and Y sus boards as well and on the main A/V board.
Reason: you might have tripped one moving board around when they may have had a voltage on them, even unplugged from the wall, never know.
The main AC line fuses should be fine since you get power.

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Okay, I have everything screwed down. I will go and check all fuses and get back to you guys...

The amber light comes on when you plug it in. When you press the power button it turns green and stays green.

[drpj23]

Re: Vizio VP50HDTV20A black screen

The power light information may not be of any relevance BUT someone else may read this and may know what is going on from that behavior of the set. That's why I asked.

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Okay, last few hours I took the set all undone. I removed every board. I checked to make sure no pins were bint or ribon cables damage. I came up with nothing there, everything looked great.

After getting the set all reassembled I took the advice from earlier and was individually undoing boards to see if it would fire up. I undone the Y main board and nothing happened. I unhooked the cable between the Y main board and the upper and lower buffer boards and on the side and now I have this....






I went and grab the upper and lower buffer board from my oter tv but I get the same thing when I put those boards in. The tv will power on but no picture. The main harness from the buffer boards has to be undone to get the picture that you see above...

So what do you guys think now?

[tom66]

Re: Vizio VP50HDTV20A black screen

That cable carries the control signals for the buffers, selecting which line on the screen to sustain. Without it, you will get garbage.

Does the screen glow at all in a dark room?

If so, I would suspect the control board. It usually has a fuse on it, check that.

[drpj23]

Re: Vizio VP50HDTV20A black screen

Hold up, if you dont have the buffer boards disconnected from the sustain board, does the relay click off?

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Hold up, if you dont have the buffer boards disconnected from the sustain board, does the relay click off?

If I have them hooked up the relay does click off... If i unhook them, I get the set to power up.

And no the set does not glow at all in dark room when they are connected.

[tom66]

Re: Vizio VP50HDTV20A black screen

Indicates a shorted buffer somewhere. Try powering up with just the top or bottom buffer.

[drpj23]

Re: Vizio VP50HDTV20A black screen

I think the "buffers" are called Y drivers in this case, I've always associated the buffers with X.

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Indicates a shorted buffer somewhere. Try powering up with just the top or bottom buffer.

The bottom connects to the upper and the upper connects to the Y main board.

[tom66]

Re: Vizio VP50HDTV20A black screen

The bottom connects to the upper and the upper connects to the Y main board.

Then try without the bottom. If you have a multimeter, you can sometimes check for shorts that way too.

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

Okay, I have been gone this week. My wife and I had our first baby and it has been very crazy. I started back wanting troubleshot this tv this evening....

Okay, I unplugged the "Y driver lower board" and this is what happens... The tv will stay on 10 seconds and display the following int he picture below. There is no way to unplug the upper board and leave the lower board in circuit. The green light comes on the front when you see the screen below, then it sounds like a relay or something kicking off and the screen goes black and the green light stays on the front. I can press the power button to turn it off. And then press power again it does same cycle over and over...

Also, I have put red squares on the picture below on the cables I undone...

So, what do you guys think now?

[sigmanuh1457]

Re: Vizio VP50HDTV20A black screen

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