e701i-a3 no picture but backlights

[freakaftr8]

Re: e701i-a3 no picture but backlights

It appears that they (?) did NOT remove the tab drivers from that side of the screen. You can still see the horizontal line from a bad tab cable. It appears that they just disconnected the corner edge board cable interconnecting the bottom edge boards to the side edge boards. They need to provide you with pictures of the removed edge boards to confirm what they have done... :-)

+1.

Did they completely remove the right hand boards?

[freakaftr8]

Re: e701i-a3 no picture but backlights

Hi I have same issue with this 70 inch tv. went ahead and ordered Tcon board replaced it disconnected right side white tab and turned it on. here are the pictures......One thing before I did all this had no picture but did have sound I don't know if its because I had nothing but internet but I had no sound?

Jim kooks like you have a problem with the right side. Is that picture with the small cable detached? Because I don't see any horizontal lines in the picture showing a defective ribbon tab. You're absolutely sure that there is a panel problem? You tried different t-con boards to no avail before you put this one in and disconnected that driver cable?

[budwich]

Re: e701i-a3 no picture but backlights

It appears that he disconnected the corner cable as you think, "fearing" that it might have originally taken out the tcon card BUT it appears that the panel isn't in trouble (tab drivers) and that the "unpowered" drivers are now loading down that side.... maybe.

[andrew77]

Re: e701i-a3 no picture but backlights

I just got through removing the side tab drivers and replacing the MOSFET on the t-con board for this TV I've had lying around for the last 6 months. I used a 771-2N7002F from Mouser since I had 12 of them in my pile of parts from another project. Seems to be working, but I have some distortion on the lower left quarter of the screen. The left side of the screen had the bad drivers. Also the last picture shows some distortion on the icons in the notification area. Anyone have any idea of what might be going on or is this normal for this TV?

[budwich]

Re: e701i-a3 no picture but backlights

it would probably help to look at the settings on the tv. Of course, it would help even more if you put on a known tv test pattern for resolution... you will likely get your answer quicker.

[andrew77]

Re: e701i-a3 no picture but backlights

I've turned off all the extra image processing things in the settings and stripped it down as much as possible. The pictures that I posted in the previous post are my results. Looks like ghosting. LCD panels can't have convergence problems can they? Don't want to jump to any conclusions or waste anyone's time with it. Everything seems to be working fine otherwise.

I wouldn't have gotten this far without this thread. Big thanks to everyone involved, especially freakaftr8.

[freakaftr8]

Re: e701i-a3 no picture but backlights

It looks as if you're having a definite vertical distortion problem. First thing I would do is try another input or a source besides a computer. VGA cables are known for having problems with shielding and I have seen distortion issues with those cables before. Can you use some other source like a DVD player or at least turn on the menu and take a picture of that? Is also a slight possibility that you might want to clean the area where you stripped the cables off with some denatured rubbing alcohol and also clean the two ribbon cables going from the tcon board to the panel also

[andrew77]

Re: e701i-a3 no picture but backlights

I'm using HDMI and I did switch to a different HDMI port, but I didn't try the VGA output. I think you're probably right about needing to clean the area I removed the cables from.

Those lines in these pictures, the smallest line is 1 pixel wide and the wider line is 2 pixels wide on the end and 3 pixels wide on the rest. The first picture is the bottom left, the next one is the middle on the right side, and the last one is part of the menu. The menu looks pretty normal, but I'll have to look at the other Vizio I had to see how it looks. I'll get a picture tomorrow to compare it. Next thing I'll try is the VGA output.

I do have another mainboard to try in it, but when I had it in it before putting everything back together it seemed like it had a lot of artifacts or something going on with it. The one that's in there right now turns out to be for an E601i-A3. Also I'll take it back apart and clean the cables as you suggested. Thanks for the help. I'll get back with you on what I find.

Edit:
I can confirm that the VGA output is slightly worse, probably due to its nature.

[freakaftr8]

Re: e701i-a3 no picture but backlights

The third picture of the menu looks normal. I dunno could be just a piece of junk still stuck to the panel

[tjmethod]

Re: e701i-a3 no picture but backlights

Hi Bud thanks I will forward the message to them and have them disconnect and when they do I'll report back hopefully with results- thanks again!

[tjmethod]

Re: e701i-a3 no picture but backlights

Hi Bud it appears that they did remove the right-hand drivers- I recall coaching them on the phone after finding out that that once disconnecting them at least put the v and HDMI info on the screen. Is the something else that could be connected that would cause the right side shadowing and tiny vertified line?
Here a pic of the right tabs removed. Thanks!

[budwich]

Re: e701i-a3 no picture but backlights

nice boards... :-)
I don't think they removed the drivers.... they just removed the boards. :-)
How can I tell?... I see NO cables attached to the sides of those boards... meaning they likely left them attached to the panel. Just my guess though. Of course, a picture of the side / back of the panel showing at least one of those cable locations.

[tjmethod]

Re: e701i-a3 no picture but backlights

Thanks Bud- now I'm even confused- I actually thought the boards were the drivers, can you tell me what the drivers consist of? Thanks again

[tom66]

Re: e701i-a3 no picture but backlights

There's a little integrated circuit ("silicon chip") mounted on the flex. If that's still connected with the board removed, faults can occur.

[freakaftr8]

Re: e701i-a3 no picture but backlights

Yes. The drivers are still connected to the panel on the side they pulled the boards from. Those drivers need to be pulled from the panel also. There's your problem. The short relies in those driver tabs.. with the boards removed but the driver still on the panel is still acting like there's a short.

What you are confused about is the fact that pulling the boards doesn't change anything. The boards only take the data from each driver and chain it to the next driver. With the board removed the drivers are still there they just cannot chain in a serial pattern.

[tjmethod]

Re: e701i-a3 no picture but backlights

Ok I've got it they are the five film tabs on both sides of the TV connecting the LCD driver boards. They didn't pay attention to my instruction the same way I did from you guys- thanks I'm going to get them all straightened out- thanks again guys

[freakaftr8]

Re: e701i-a3 no picture but backlights

Right. Only remove the bad side. Lol the way you worded it sounds like they're going to be removing both left and right sides from the screen.

[budwich]

Re: e701i-a3 no picture but backlights

Ok I've got it they are the five film tabs on both sides of the TV connecting the LCD driver boards. They didn't pay attention to my instruction the same way I did from you guys- thanks I'm going to get them all straightened out- thanks again guys

Yikes... make sure what you are saying.... YES, you have to make sure that you remove BOTH ENDS of the cable .... not BOTH SIDES OF THE TV..... its amazing how confusion starts.... :-)

[Nick's Tvs]

Re: e701i-a3 no picture but backlights

Does anyone know if this would work for a vizio M401i-A3?
The panel board that has the bad drivers is part DUNTK4813TP.
The actual panel number I am not sure.
Edited for improper terminology

[budwich]

Re: e701i-a3 no picture but backlights

It only works IF there are drivers running on both sides of the set. It is unlikely that smaller panel sizes utilize this technique.... even the e60 do not. Further it is NOT a board issue in most / all cases. The driver is in the tab cable.