Vizio VX37LHDTV10A - Mysterious Screen

[dsberger]

I have a Vizio VX37LHDTV10A and am experiencing the exact problem showcased in this video. (this video is not my actual TV, but as I mentioned, I am having the exact same issue).
http://www.youtube.com/watch?v=2WbYxkQ32ns

I purchased in 2008 from Sam's Club and it is out of warranty. I have cracked open the back cover/case and visually examined the capacitors (caps). None of which appear to be loose or "domed" as would normally indicate failure. Plus, I am not experiencing the frequent power cycle problems that others experience with capacitor failure.

When the set is plugged in, power is turned on, the TV picture comes on just like in the video … gray bars gradually appear. No function buttons will work on the side of the set or with the remote. Only unplugging the TV will turn it off.

Does this sound like the video board, the control board (I'm not sure if I know the difference.) The control board seems like it would be the board where everything plugs in at the rear of the TV (HDMI, Optical cable, Audio L, Audio R, Video, etc...) It is mounted horizontally.

There is another board on this model, that is long and mounted vertically on the left hand side (when viewed from the rear) and on the same side as the power button. I'm not sure what this board is.

Both board seem like they would be relatively simple to replace, just not sure which one it would be considering the mysterious video.

Any help, suggestions are welcomed.
David
dwsberger

[tom66]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Pictures will be essential, but I've seen a similar problem with my Xerox XA7-19i: the picture would start off completely white (if you looked very carefully you could see the input video) and parts would slowly fade away until you were just left with a black screen. In my case, it was bad capacitors.

[PlainBill]

Re: Vizio VX37LHDTV10A - Mysterious Screen

I have a Vizio VX37LHDTV10A and am experiencing the exact problem showcased in this video. (this video is not my actual TV, but as I mentioned, I am having the exact same issue).
http://www.youtube.com/watch?v=2WbYxkQ32ns

I purchased in 2008 from Sam's Club and it is out of warranty. I have cracked open the back cover/case and visually examined the capacitors (caps). None of which appear to be loose or "domed" as would normally indicate failure. Plus, I am not experiencing the frequent power cycle problems that others experience with capacitor failure.

When the set is plugged in, power is turned on, the TV picture comes on just like in the video … gray bars gradually appear. No function buttons will work on the side of the set or with the remote. Only unplugging the TV will turn it off.

Does this sound like the video board, the control board (I'm not sure if I know the difference.) The control board seems like it would be the board where everything plugs in at the rear of the TV (HDMI, Optical cable, Audio L, Audio R, Video, etc...) It is mounted horizontally.

There is another board on this model, that is long and mounted vertically on the left hand side (when viewed from the rear) and on the same side as the power button. I'm not sure what this board is.

Both board seem like they would be relatively simple to replace, just not sure which one it would be considering the mysterious video.

Any help, suggestions are welcomed.
David
dwsberger

I'd suspect a bad panel or bad tcon.

PlainBill

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

I have taken pictures of the various boards in hopes that this forum can direct me on which board is what and how to run a diagnostic on each (if possible). Not sure if I know the difference between a panel or a T-Con.

I have arranged the pictures into three groups, A, B and C, and then subsequently numbered them.

Group A seems to be the main board and has lots of capacitors and clearly a processing chip. None of the capacitors shows any visible signs of being faulty (domed or being loose).

Group B appears to be the power supply board and features a much smaller amount of capacitors under a heat sync. Again, none of which show any physical damage.

Group C is the backlight inverter, no visible capacitors. It's also stamped with high-voltage warnings.

You've seen the video I posted of the problem I'm having ... what's next? My thought was, once I figure out what each board does, I might be able to deduct which board may need replacing based upon the problem I am seeing on the screen. Thoughts?

[PlainBill]

Re: Vizio VX37LHDTV10A - Mysterious Screen

I have taken pictures of the various boards in hopes that this forum can direct me on which board is what and how to run a diagnostic on each (if possible). Not sure if I know the difference between a panel or a T-Con.

I have arranged the pictures into three groups, A, B and C, and then subsequently numbered them.

Group A seems to be the main board and has lots of capacitors and clearly a processing chip. None of the capacitors shows any visible signs of being faulty (domed or being loose).

Group B appears to be the power supply board and features a much smaller amount of capacitors under a heat sync. Again, none of which show any physical damage.

Group C is the backlight inverter, no visible capacitors. It's also stamped with high-voltage warnings.

You've seen the video I posted of the problem I'm having ... what's next? My thought was, once I figure out what each board does, I might be able to deduct which board may need replacing based upon the problem I am seeing on the screen. Thoughts?

You are missing one board. Notice the cable in the upper left corner of the first picture. That runs to the tcon board.

PlainBill

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Missing tcon board photographs aside, is there any way to run a diagnostic on each board so that I may determine which board is malfunctioning? I have a volt meter (just not a great idea on how to use it).

[f67bird]

Re: Vizio VX37LHDTV10A - Mysterious Screen

My guess would be a bad main board (the board with the antenna and video/audio inputs).
If the set locks up and wont turn off, I think its the main suspect...it could possibly also cause the symptoms on the screen.

[fastvideo]

Re: Vizio VX37LHDTV10A - Mysterious Screen

A photo of the T con board is the best to see if that is the famous 400WHC8LV1.3 problem.

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Ok, if a photo of the TCon board is what you need then here you are. Again, I see no obvious physical signs of damage.

I still haven't received an answer from anyone on how to run a diagnostic on any of these boards to test if they are bad. Obviously the screen is indicating that something is wrong by displaying those vertical gray bars (see video at beginning of thread). The answer has to be here somewhere. Can we start ruling out any of the following parts:
- Backlight Inverter
- Main Board
- Power Supply
- T Con Board
- any of the various cables/ribbon cables

[tom66]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Ok, if a photo of the TCon board is what you need then here you are. Again, I see no obvious physical signs of damage.

I still haven't received an answer from anyone on how to run a diagnostic on any of these boards to test if they are bad. Obviously the screen is indicating that something is wrong by displaying those vertical gray bars (see video at beginning of thread). The answer has to be here somewhere. Can we start ruling out any of the following parts:
- Backlight Inverter
- Main Board
- Power Supply
- T Con Board
- any of the various cables/ribbon cables

It's pretty difficult to diagnose without an oscilloscope; a multimeter will even tell you power supply voltages are okay if you've got bad caps as it measures average voltage.

If you disconnect one(only one) of those cables going to the LCD from the TCON, what happens? Same problem?

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

If you disconnect one(only one) of those cables going to the LCD from the TCON, what happens? Same problem?

Let me hook things back up and give this a try. (had to disassemble everything in order to even get down to the TCon board). Stupid question time: the ribbon cables (2 of them) connecting the TCon board to the LCD seem very fragile and small. Do they simply pull apart from the TCon board, or is there a special trick I need to know? I just don't want to screw this part up.

Thanks in advance for your help/suggestion. I will let you know how the experiment goes.

[momaka]

Re: Vizio VX37LHDTV10A - Mysterious Screen

the ribbon cables (2 of them) connecting the TCon board to the LCD seem very fragile and small. Do they simply pull apart from the TCon board, or is there a special trick I need to know?

Depends on the connector. On some, you pull a piece of plastic out in the direction of the ribbon cable. On others, the top side of the connector may open and close like a hinge. Yet still on others, you just pull on the ribbon cable and it comes out.
Yours has 2 different colors of plastic - white and brown. The white one seems to be attached to the connector base where it is soldered, so it probably doesn't move. The brown plastic however, may either have to be pulled out a bit or lifted like a hinge. Try doing both with a small screwdriver or something like that to see if it moves in any direction. If it doesn't force it -after all, it's also possible that you just have pull on the ribbon cable and that's it.

[tom66]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Here's what a Dell 15" does when the LVDS connection is loose.

Very similar symptoms: fading from white into darkness, faint lines visible, etc.

I deliberately loosened the connector to get this. Just reseat the connector - also make sure that the connector is clean from dust and dirt.

http://www.youtube.com/watch?v=bnfymg6ip6A

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

I have tried disconnecting one ribbon cable and the screen goes dark (no vertical gray bars). I reconnect both ribbon cables and the vertical gray bars re-appear.

Is this a clear indicator of a bad TCon board?

Power button (on side of set and remote) do not have effect on TV. Must un-plug set in order to kill the power.

I can get a TCon board for around $55-$60 + shipping. Thoughts?

[tom66]

Re: Vizio VX37LHDTV10A - Mysterious Screen

I have tried disconnecting one ribbon cable and the screen goes dark (no vertical gray bars). I reconnect both ribbon cables and the vertical gray bars re-appear.

Is this a clear indicator of a bad TCon board?

Power button (on side of set and remote) do not have effect on TV. Must un-plug set in order to kill the power.

I can get a TCon board for around $55-$60 + shipping. Thoughts?

Not necessarily. See the cable which goes from the motherboard (with the video input connectors) to the TCon? Check that one too - that was the one I was fiddling with on my Dell 15".

It's possible, if the TV does not switch off, it is a more serious problem with the motherboard, or the power supply.

Do you have a multimeter to test the supply voltages?

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

It's possible, if the TV does not switch off, it is a more serious problem with the motherboard, or the power supply.

Do you have a multimeter to test the supply voltages?

Which board would you consider the motherboard? (the main board?)
I do not have a multimeter but could probably pick one up at RadioShack, no idea how to use it however.

On the power supply board, there is a small fuse that can by removed. Any chance it can be something stupid and easy such as this? I suppose if the fuse were blown, the TV wouldn't even power on, correct?

[Elirod91]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Hello, iv just acquired a vizio VX37LHDTV10A from a friend, it has the same problem that you were experiencing, did you ever find out what the problem was?

[dsberger]

Re: Vizio VX37LHDTV10A - Mysterious Screen

Dear Elirod,
Unfortunately, I never did find out the source of the problem. I took apart the tv and found all the boards but could never find any way to perform deductive diagnostics on each board. Part of me was hoping to take the tv apart and find a shoelace untied, but it's never that easy. I gave up and purchased a new tv.

The ironic part, I purchased another Vizio which started to have problems shortly after I bought it. It would turn off with no warning. Thankfully it was under warranty and replaced at no charge. Still, if I had to do again I would buy a different brand, not Vizio.

Good luck!