e701i-a3 no picture but backlights

[freakaftr8]

Re: e701i-a3 no picture but backlights

That's interesting, however I do not believe this is a panel issue, first I would try resetting the TV to factory defaults and if that doesn't seem to help reseat the cables again and then I would say mainboard problem as you can see the pixelation in the screen. Does it seem to do this with any kind of input? How about plumbing Aaron through a VGA connection.

Also I would definitely try reseating the LVDS cables on the tcon as well as the mainboard . There are two cables. Reseat both of them and also try to clean it with alcohol

So I thought I would try and fix another 70" as I had success the first time but I have ran into a problem, quick version. after removing tabs, new t-con tv is now working again but the screen quality isn't very good real pixelated / gassy looking pictures attached. I have tried cleaning all cables changed setting but nothing seems to be helping. Thnaks

[gormanrider8]

Re: e701i-a3 no picture but backlights

You notice how everything looks nice and clean and perfect on the right side of your screen but the left side is dark you got some lines going through it where the lines ascending horizontally are keeping up with the right side of the screen which is still connected to the Tcon. This is because the left drivers are shorted out just remove them off the screen completely

Thanks freakaftr8, I'm ready to pull the left drivers off tonight. But what about my TCON? Is it possible to get the image I am getting with a blown FET? I'm going to replace the FET on one of my tcon's today but am still worried I could be replacing the wrong FET as my board is different. When I power on after pulling the drivers, is there a possibility for more damage if I power on with a bad TCON? Or will I notice some image artifacts of some sort?

Right now I am planning on leaving the same TCON in (with a suspected blown FET) I have used in all of my tests for when I power up after removing the left drivers. If I see something unusual, I will power off and switch to the tcon with the replaced FET and hope that eliminates any issues.

[freakaftr8]

Re: e701i-a3 no picture but backlights

No I'm confident your tcon is good. You would have other symptoms.

[euroryde]

Re: e701i-a3 no picture but backlights

Ya the picture posted is after cleaning the cables with a alcohol resea ting them. Same pixalation issue with just the menu, Netflix, hdmi and reseting. Will order up a main board and give that a shot. Thanks

[budwich]

Re: e701i-a3 no picture but backlights

hmmmm... thanks for the interesting picture. As Freakaftr8 indicated, I don't think you have a tcon issue (or at least, a bad fet is not likely). Related to the "cable disconnection", not sure if I now know where things lie, so maybe a recap if you don't mind. The picture you posted is with one corner flex cable removed... correct? If you disconnected (ie switch sides) the other side, you get no picture... correct? Although, I understand you don't want to do that for too long as it could take out the tcon.

IF the above statements are still true, I would still say you have at the very least a panel issue. Things to note from my limited experience and readings, that the failure of a tab driver is NOT uniform and can provide a broad range of "visual sypmtoms". BUT the disconnection of the corner cables is usually a pretty reliable "mode" for determining that the panel is the problem especially after checking / changing other items out.

[budwich]

Re: e701i-a3 no picture but backlights

Further on all this. As suggest by freakaftr8, double check your cable "clamping" on the various cables... WITH YOUR GLASSES ON.... :-) .... there have been some here that have had "visual challenges" and have caused their own problems.... so either glasses or magnifying glass... compare all the connectors, physical positioning / placement... all "markings" / "visual references" should look the same.

After that, if things haven't improved, and you are now relatively sure that you have disconnected the appropriate corner cable to indicate that side is the issue, I would carefully disassemble that side frame / bezel to get clear access to the tab driver cables on that side. Carefully, "unclip" the boards (board holder clamps) so that you can readily / carefully turn them over to look at the undersides of the tab cables / driver. What do the 5 cable drivers look like.... any heat markings? Do this very carefully as you don't want to actually make a "failure"... :-)

DO NOT TRY to disconnect the tab drivers just yet!

[Jim1590]

Re: e701i-a3 no picture but backlights

First I would check and make sure you didn't blow out your teeth on morning. Sounds like possibly you didn't have the ribbon cable seated Properly. When you plug in the bad side you might have taken out the transistor again But yes once you find your bad side the good side will show a decent 1/3 half of a picture precedent dark and blurry with most likely a few lines going through the screen. So it kind of sounds like your Right side facing the front might be the failure point However before you do this why don't you try supplying and some input or signal to it while you say goes blank. These TVs will go into immediate standby if it's set in PC mode where it's trying to accept a VGA signal so make sure that's not the case

I re-seated all of the cables and I swapped the main board with another one that came with the tv. Figured why not. The following pictures are with the left side looking at the display (right side when looking at the tcon) ribbon cable disconnected from the driver boards. I only got the menu up, I do not have any nearby sources, but if it is really needed, I can get one to the tv.

When I took these pictures, I had no problems whatsoever besides the lines. The TV stayed on and I was able to bring up the menu and such.

I do have a New tcon that arrived yesterday. I did not want to put that one in until I was fairly confident it would not get fried. The tcon in place for these pictures is my repaired one.

The last picture is a mostly clear view of the repair.

Whats my next step?

[gormanrider8]

Re: e701i-a3 no picture but backlights

hmmmm... thanks for the interesting picture. As Freakaftr8 indicated, I don't think you have a tcon issue (or at least, a bad fet is not likely). Related to the "cable disconnection", not sure if I now know where things lie, so maybe a recap if you don't mind. The picture you posted is with one corner flex cable removed... correct? If you disconnected (ie switch sides) the other side, you get no picture... correct? Although, I understand you don't want to do that for too long as it could take out the tcon.

IF the above statements are still true, I would still say you have at the very least a panel issue. Things to note from my limited experience and readings, that the failure of a tab driver is NOT uniform and can provide a broad range of "visual sypmtoms". BUT the disconnection of the corner cables is usually a pretty reliable "mode" for determining that the panel is the problem especially after checking / changing other items out.

Thanks again for the feedback. I have re-seated all ribbon cables multiple times and cleaned the cables and connectors with IPA. Still same results. The first picture is the result with the LEFT side corner ribbon cable removed. The second picture is the image with BOTH side corner ribbon cables removed. I am hesitant to plug in only the left corner cable as that is certainly the offending side and I don't want to smoke a TCON. The third image is the result with BOTH side corner ribbon cables INSTALLED. As you can see from the picture, I get the same results when I have only the RIGHT corner ribbon installed as when I have BOTH corner ribbons installed.

The side drivers on the left side aren't obviously smoked/heat damaged/etc. but two tabs do look a tiny bit discolored around the middle of the tab near what I think is the IC people have referred to. However, when I lightly press on the side tabs some rows of pixels come back to life then disappear when I release pressure.

I am now very convinced the LEFT side drivers are bad. Might take the chance and pull them off now. Thanks for your help again and let me know if anyone has another hypothesis other than the left side drivers.

[freakaftr8]

Re: e701i-a3 no picture but backlights

Jim1590 give me a picture with something playing on the screen but you definitely have a bad driver

gormanrider8. Go for it. That's your problem

[Jim1590]

Re: e701i-a3 no picture but backlights

Jim1590 give me a picture with something playing on the screen but you definitely have a bad driver

gormanrider8. Go for it. That's your problem

Will do. Probably tomorrow night or the weekend.

Thanks

[budwich]

Re: e701i-a3 no picture but backlights

You are likely on the right track BUT I just want to clarify things for you. You seem to be referring to the "drivers" as perhaps referring to the side boards while indicating that the tabs have some discoloration.... ??? The drivers that we are talking about ARE on the tab cables going to the panel (the ones you are saying are discolored... I think). The boards are not the drivers and are likely not an issue... but they do have to be removed to solve your issue. When you are about to remove the "infected" tabs, you will see the drivers on the other side... which are likely causing the discoloration.

[gormanrider8]

Re: e701i-a3 no picture but backlights

Jim1590 give me a picture with something playing on the screen but you definitely have a bad driver

gormanrider8. Go for it. That's your problem

Wooooooo! Removed the left side driver tabs and perfect picture! THANK YOU all so much I definitely couldn't have done it without freakaftr8. Thanks for being so responsive and helpful. I have it fully set up and looking great with cable through HDMI.

Cheers.

[freakaftr8]

Re: e701i-a3 no picture but backlights

Sweet! Nice job! Congrats

Wooooooo! Removed the left side driver tabs and perfect picture! THANK YOU all so much I definitely couldn't have done it without freakaftr8. Thanks for being so responsive and helpful. I have it fully set up and looking great with cable through HDMI.

Cheers.

[Jim1590]

Re: e701i-a3 no picture but backlights

Lower left cable is disconnected as we are looking at the TV display.

The test signal is actually a video I was running via plex that I downloaded from here:

https://vimeo.com/41414940

Also concerned about the clarity of the image. I do have a new tcon that I can put in once I know I am not going to short it. Also have another main board tha tmay be working, may not.

[budwich]

Re: e701i-a3 no picture but backlights

The first three pictures "appear" to confirm that side driver(s) have an issue. The confusing one is the last one, it looks pretty good.... what's up?

Never mind... you were just provide a "screen shot" of the test pattern software... :-)


As for clarity, you can't judge that until the "operation" is complete as the "faulty drivers" impact the whole visual display. I think you are going to have a spare tcon... :-)

[freakaftr8]

Re: e701i-a3 no picture but backlights

Yes Jim that left side is bad. Telltale sign is the nice bright working bar in the middle. Remove the left side drivers and boars off the side of the panel on the left side. This is the left side as you are facing the front of the TV watching it. Watch my video for instruction on how to do so.

[Sandman262]

Re: e701i-a3 no picture but backlights

First of all BIG THANK YOU to freakaftr8 for this thread and the "freak solution" to fix these e701 Vizio TVs!

Second, add me to the list of folks that were able to fix their TVs using the freak solution. After the "surgery" the TV works with no identifiable issues. Even more important: I will be able to watch the Super Bowl on the 70" TV vs the small 42" we were using as temp solution!! Especially important since I live in the Carolinas ... GO PANTHERS, KEEP POUNDING!!!!

Third here some lessons learned from my fix experience that may help other badcaps members attempting the fix:

- When you disconnect one of the side drivers, and have the BAD one still connected (I started removing the right one first, where Vizio sign is, but in my case left driver was bad) you still will only see a blue screen as if nothing changed. You will be guessing if you did something wrong or if your TCON board is bad or you blew your TCON.

- Found a good youtube video on procedure to check your TCON board https://www.youtube.com/watch?v=yTnkOfwBGGE. (I initially thought that my TCON I bought from eBay was bad or I had blown it when initial test of the fix procedure and therefore was getting blue screen, but after running test was able to confirm that it was OK)

- Go thru the effort of removing the black metal covers of the side drivers, it is well worth the extra time. I damaged one of the ribbon cables connecting the bottom drivers to the right side driver when trying to pull the ribbon cable out. Good News, you can use the ribbon cable from the other side (which you do not need anymore after the surgery) as replacement! In my case the left side driver was bad and was able to use of the right side (Vizio symbol side).

- I also damaged one ribbon cable holding tab (black/grey part) on the bottom driver (same reason like above). Good news, you can carefully remove one of the tabs from the bad driver (which you are going to toss anyway) and re-use to fix. Worked for me

Good Luck!

[Jim1590]

Re: e701i-a3 no picture but backlights

And it is DONE! Removed the left side drivers by the control buttons and have a great picture.

Swapped my repaired board for the new one I got and the tv would not display a picture. V for a few seconds then black. Repeated several times. Hmmm.... put the repaired board back in and enjoyed watching tv on it. Board going back.

This is the first time using this TV, or anything this big. Picture is not as sharp as I was expecting. Not as clear so to speak. Probably the settings or my input.

On a side note, anyone know what size screws hold the back cover on? The previous owner did not seem to keep all of them together. I am missing about 10 of them. Hit the corners and the bottom and thats it.

Thanks for all of the advice!

[euroryde]

Re: e701i-a3 no picture but backlights

So got in another main board today tried it out and still the same bad pixelation, wondering now if something could be up with the t-con board. :/

[budwich]

Re: e701i-a3 no picture but backlights

could be ... but as suggested to others, post pictures of a known test pattern. That way people will know a bit better what to expect and may have suggestion on what they see.