Vizio M550NV No picture, backlights work.

[SHADOW3277]

Hello. I have a Vizio M550NV that when I turn on, the backlights kick in and I can see the panel light up but I get no picture.

When I unplug the right side of the TCON and leave the left side plugged in, I get half a picture on the screen and the other half is a white screen.

When I unplug the left side and plug the right side in, I get no picture just the lighted panel from the backlights.

I'm wondering if it is a bad TCON or maybe the panel? I did look at the other threads on this model but couldn't find an answer.

I can't upload pictures until Monday. I don't have my digital camera at my house with me and my cell phone camera sucks, the pictures would be too blurry.

[audiofreak19]

Re: Vizio M550NV No picture, backlights work.

The panel is bad. I had the same problem with the same model tv.

[audiofreak19]

Re: Vizio M550NV No picture, backlights work.

Basically what has happened is half the screen is shorted so when u unplugged the one side it allows the good half to play. And when you have both plugged it it recognized the short and cuts all video to prevent the other side from shorting

[SHADOW3277]

Re: Vizio M550NV No picture, backlights work.

The panel is bad. I had the same problem with the same model tv.

Damn that sucks. I was afraid it was the panel. Thanks for the reply.

[xtremeskier97]

Re: Vizio M550NV No picture, backlights work.

I hate to bump old threads, but this is exactly what my M550NV is doing. I can disconnect 1 of the cables from the T-Con and half the screen works but when I reverse it, the other half does not.

What I want to know is, if I put the cable for the side of the TV that did not work in the above test into the side of the T-Con board that DID work, would this tell me for sure if it's the T-Con board is bad or if it's indeed the panel?

My logical thinking is that, if I put the cable of the working side into the "non-working" side of the t-con and the panel is actually good, then it would show the good side of the t-con boards graphics on the other side of the screen. Basically, the left half of my screen would show on the right side of the panel.

Does this make sense, or did I not explain it good enough?

Basically, I want to know, FOR SURE, if it's the T-Con board or if it's the Panel thats bad, and this is the only way that I can think to know for sure without spending over $100 on another T-Con board to swap it with.

Thanks guys!

[budm]

Re: Vizio M550NV No picture, backlights work.

'What I want to know is, if I put the cable for the side of the TV that did not work in the above test into the side of the T-Con board that DID work, would this tell me for sure if it's the T-Con board is bad or if it's indeed the panel?' Did you try it and see if the supposedly bad side does give you pictures? That is one way to find out. If the panel is bad, that side will stay bad due to bad ICs on the flexible PCB for the TFT drivers.

[xtremeskier97]

Re: Vizio M550NV No picture, backlights work.

Did you try it and see if the supposedly bad side does give you pictures? That is one way to find out. If the panel is bad, that side will stay bad due to bad ICs on the flexible PCB for the TFT drivers.

So this test I'm describing should tell me for sure whether it's the t-con or the panel?

Is there a possibility of messing anything up by performing this test?

[budm]

Re: Vizio M550NV No picture, backlights work.

So this test I'm describing should tell me for sure whether it's the t-con or the panel?

Is there a possibility of messing anything up by performing this test?

Both cables are the same with the same numbers of pins, right? They should be the same so no problem swapping them, just make sure it is properly seated.

[xtremeskier97]

Re: Vizio M550NV No picture, backlights work.

Both cables are the same with the same numbers of pins, right? They should be the same so no problem swapping them, just make sure it is properly seated.

I'll try this tonight and post results.

Thanks!

[Paul J]

Re: Vizio M550NV No picture, backlights work.

Somebody gave me a M550NV today that does this also, or similar. Turns on with remote, backlights work, has sound, but no picture. So I'll follow your post if you dont mind.

[xtremeskier97]

Re: Vizio M550NV No picture, backlights work.

Well, I tried what I described above. No dice.

When I diconnect the left (looking at the back of the tv) ribbon cable from the t-con board (middle board) the left side (looking at the front of the tv) of the screen works. When I do the opposite, no part of the screen works.

So, I hooked the left cable to the right side of the t-con board, hoping the left side of the display would show on the right side of the screen. Nothing.

Then I hooked the right cable to the left side of the t-con board, hoping the right side might show on the left side of the screen. Nothing.

So either both my panel AND my t-con board are bad on that side OR swapping those 2 cables wouldn't work even if everything on the TV DID work.

So at this point, I've got a local guy willing to give me $60 for the tv. I might just do that. Haven't decided yet.

Paul J, have you already tried disconnecting 1 of the bottom ribbon cables going from the t-con board to the panel? If not, that is the first thing I'd try, as it's the easiest. Disconnect 1 of them and turn the TV on and see if half the screen works. Then do the opposite cable. Post your results.

[xtremeskier97]

Re: Vizio M550NV No picture, backlights work.

Paul, I'd be interested to know if your results of disconnecting 1 cable and testing, then disconnecting the other cable and testing, allow the left or right side (looking at the front of the tv) of the screen to work.

[Paul J]

Re: Vizio M550NV No picture, backlights work.

Ill try that, this was going to be a winter project as Im swamped with my regular landlord job. I looked closely tonight with a magnifying glass and it seems the TCON board is a bit waxy, wet looking. In fact, some of the white labels are 1/2 saturated though I see no bad caps, none obvious anyway. I guess adj voltage regulators with the middle leg cut off is normal. I'll try the ribbon test tonight if time allows. Thanks guys. PS, I didnt know this tv was this old, power supply says 2002?

[Paul J]

Re: Vizio M550NV No picture, backlights work.

So, Viewing from the rear of the tv, disconnecting the left bottom cable on the tcon made the right side (viewing from the front) of the tv turn white., I admit I have nor scource hooked up at this point as this would take a little time. There is also a faint blue line to the extreme left of the picure viewing from front. I see no tv messages such as "no input" or similar.