e701i-a3 no picture but backlights

[suprteacher]

Re: e701i-a3 no picture but backlights

OK... so perhaps that damage is not a "physical result" of manipulation but potentially an "electrical result"... a short causing "arcing" / burning of the contact there in / on the cable. Hope not.... but you may need to trace that path to the edge board at the bottom of the set. At that point, get a meter and do some resistance measurements (to ground) to see what's up.

Going from ground to each of the contacts on the panel where the ribbon plugs in? What am I looking for? Thx

[budwich]

Re: e701i-a3 no picture but backlights

OK... so perhaps that damage is not a "physical result" of manipulation but potentially an "electrical result"... a short causing "arcing" / burning of the contact there in / on the cable. Hope not.... but you may need to trace that path to the edge board at the bottom of the set. At that point, get a meter and do some resistance measurements (to ground) to see what's up.

[suprteacher]

Re: e701i-a3 no picture but backlights

I think you misunderstand what I asked. I wasn't expecting that reversing the cable ends would get you a picture or improve the situation. What you needed to check was what happens when you put the "reversed end" into the tcon connector... do you end up with the SAME "physical damage" in the same area? That's what you needed to verify.

No I did not. No physical damage to the other end.

[budwich]

Re: e701i-a3 no picture but backlights

I think you misunderstand what I asked. I wasn't expecting that reversing the cable ends would get you a picture or improve the situation. What you needed to check was what happens when you put the "reversed end" into the tcon connector... do you end up with the SAME "physical damage" in the same area? That's what you needed to verify.

[suprteacher]

Re: e701i-a3 no picture but backlights

:-( certainly appears that you have found an issue. The question is what is causing the problem especially since you switched cables and it appears now the "switch" has caused the other cable to have a similar issue. The last picture is not clear enough to see any problems with the connector. You need to look very closely... maybe using some form of magnification to check the area.

With the power off, can you put back the cable the way it would be normally and take a close up of the area again. This will show us how you are "seating" the cable. Take a picture of one of the other cables that is currently seating to compare.

Further, from the way that the cable is "damaged", you are likely not going to be able to easily see the problem from the "front" as it is likely in the "last miillimeter" IF it exists.

IF you are lucky, you should be able to find replacements.... BUT you need to find the ROOT cause otherwise you will be just repeating the "failure".

Further, the cable may "saved" with some very careful trimming to remove the millimeter or so of the bad end.... I think some have done it in the past... but it is probably a long shot depending on your skill and tools. Still further, now that you know where the problem "starts" and that you may have ruined a couple a cable ends... don't do much more with that connector in terms of inserting... BUT I do believe that the cables might be reversible... meaning that the other can be switched around to insert into the "bad connector". This could be a ONE TIME test... to see if inserting into the connector causes the damage. Take the other end of a bad cable and check it to see that is "good". IF so, try inserting it into the connector, clamp, then unclamp and remove. IS the result, a now damaged cable? Hopefully you understand.... good luck.

I tried reversing the cables with the ends that go to panel now going to tcon board and the end that used to go to tcon board now going to the panel. I get the exact same result.

I then tried fixing the ribbon cables by 'trimming' the problem area off the end. I then seated the cables back in and have the exact same result.

I am able to jiggle one cable to get the middle bar to change colors, but it never brings up a picture. The new messed up section on the right side is now stuck in that multicolored vertical bars, never changing while jiggling either cable.

Throughout my research, it is looking more like the bottom panel now has something messed up. I wonder if I'll be able to take any of the driver's from the bad panel and be able to fix the bottom drivers?

My next step is to get a new tcon board and new ribbon cables I guess to double check that the bottom drivers are actually the problem.


While waiting on the new parts, I'm going to gently move the rest of the bottom led driver cables to see if the tab bonding is the problem. Hopefully this isn't the case.

Thanks for all the help. I'm wondering if in my haste to fix, I screwed something else up that wasn't broken in the beginning.

[budwich]

Re: e701i-a3 no picture but backlights

:-( certainly appears that you have found an issue. The question is what is causing the problem especially since you switched cables and it appears now the "switch" has caused the other cable to have a similar issue. The last picture is not clear enough to see any problems with the connector. You need to look very closely... maybe using some form of magnification to check the area.

With the power off, can you put back the cable the way it would be normally and take a close up of the area again. This will show us how you are "seating" the cable. Take a picture of one of the other cables that is currently seating to compare.

Further, from the way that the cable is "damaged", you are likely not going to be able to easily see the problem from the "front" as it is likely in the "last miillimeter" IF it exists.

IF you are lucky, you should be able to find replacements.... BUT you need to find the ROOT cause otherwise you will be just repeating the "failure".

Further, the cable may "saved" with some very careful trimming to remove the millimeter or so of the bad end.... I think some have done it in the past... but it is probably a long shot depending on your skill and tools. Still further, now that you know where the problem "starts" and that you may have ruined a couple a cable ends... don't do much more with that connector in terms of inserting... BUT I do believe that the cables might be reversible... meaning that the other can be switched around to insert into the "bad connector". This could be a ONE TIME test... to see if inserting into the connector causes the damage. Take the other end of a bad cable and check it to see that is "good". IF so, try inserting it into the connector, clamp, then unclamp and remove. IS the result, a now damaged cable? Hopefully you understand.... good luck.

[suprteacher]

Re: e701i-a3 no picture but backlights

thanks for the added info... it does help but also opens up questions.

Quote: "Once I figured that out, I completely removed the LCD and ribbon from the glass. I then put the screen back together" ... this is probably a "misstatement" I hope. Handling that actual panel layers is a very "dangerous task". I hope what you did was remove the top plastic bezel which gives you access to the "tab tapes" on the side of the "glass panel" which you then removed along with the edge board / drivers which the "tape" was soldered to.... right? People only have to take apart the panel / layers if they are looking to replace the LED backlights which I assume you did not do / did not need.

Certainly post a picture of the cable ... as good as possible so the forum can see what you are referring to... it is a good chance that it is you problem and that the tv itself is actually "fine" ... or as fine as those already saved by this method (tab removal).

I didn't go that far, but I did need to get it down as far as the guy did on his video on pg 49.

You are correct. I only went down to where I could safely remove the tab tapes

I took a couple pics. First one is what tv looks like now. Identical area of both sides of screen (just different colors). Next couple pics are of the 2 ribbon cables where I see what looks like a problem. Last pic of of the slot where the ribbon cable goes into the LCD from the tcon board.

[budwich]

Re: e701i-a3 no picture but backlights

thanks for the added info... it does help but also opens up questions.

Quote: "Once I figured that out, I completely removed the LCD and ribbon from the glass. I then put the screen back together" ... this is probably a "misstatement" I hope. Handling that actual panel layers is a very "dangerous task". I hope what you did was remove the top plastic bezel which gives you access to the "tab tapes" on the side of the "glass panel" which you then removed along with the edge board / drivers which the "tape" was soldered to.... right? People only have to take apart the panel / layers if they are looking to replace the LED backlights which I assume you did not do / did not need.

Certainly post a picture of the cable ... as good as possible so the forum can see what you are referring to... it is a good chance that it is you problem and that the tv itself is actually "fine" ... or as fine as those already saved by this method (tab removal).

[suprteacher]

Re: e701i-a3 no picture but backlights

ok... that's good and bad. It appears to show that there is something up in the area. How are switching / reseating the cables. You are releasing the clamps and then lightly lifting the ribbon which should then "pop / spring out" from the connector just based on ribbon "flex" / tension. You need to look closely at the cable itself to ensure all the conductors are ok (lightly gold plated, i think). Further look under the clamp to see if things are ok there with the pins / "fingers". Further, the cabling associated with the "lines"... is this on the same side that you indicated was the "bad side". Lastly, when you said you fixed your set, what exactly did you fix?

I'll be completely honest..this is my first tv repair and haven't really taken as much care as needed. I am an elementary teacher by day and tinkerer by night..usually dealing with small engines. The delicacy needed for TV's is much different as I'm learning.

I've been undoing the clamp on the ribbon cables and pulling down on them instead of up. When I put them in I push them up then clamp down. Another area where I show my being a novice at this.

Glad I got a free m series instead of the e since the m series is like the Sony and sharp sets where there is a protection mode to not short out the tcon.

When I picked up the tv, it would only turn on to backlight..no Vizio logo, no menu, no volume control.

To do the 'fix' I followed the steps to figure out which side of the panel was bad by undoing the small white ribbon connector on the left side. Got lucky that was the correct side. Once I figured that out, I completely removed the LCD and ribbon from the glass. I then put the screen back together and send the pictures you saw earlier.

Once I couldn't figure out why the screen had the vertical lines, I then started looking at the LCD boards on the bottom where they connect from the tcon through the lvcd (I think that's the name) cable. I took the ribbon cables and tried switching them to see if the problem happened on the other side.

The problem now is that I see a spot in the ribbon cable conductor where it looks like there's a bent pin or something that caused it to look darker. Unsurprisingly both ribbon cables have that problem now and the other side of the tv screen is doing something similar.

Sorry for rambling on. Just getting frustrated at myself for not researching more before tinkering. I'll post a picture of what the ribbon cable connector looks like as well as a picture of the screen now.

I'm hoping I can figure out the pin that's bent and fix it, then get a couple new cables, and put them on the correct way.

FYI..the part of the ribbon that's messed up is where it would enter the lcd, not the tcon side.

Thank for the help. I'm hopeful this set can be salvaged.

[budwich]

Re: e701i-a3 no picture but backlights

ok... that's good and bad. It appears to show that there is something up in the area. How are switching / reseating the cables. You are releasing the clamps and then lightly lifting the ribbon which should then "pop / spring out" from the connector just based on ribbon "flex" / tension. You need to look closely at the cable itself to ensure all the conductors are ok (lightly gold plated, i think). Further look under the clamp to see if things are ok there with the pins / "fingers". Further, the cabling associated with the "lines"... is this on the same side that you indicated was the "bad side". Lastly, when you said you fixed your set, what exactly did you fix?

[suprteacher]

Re: e701i-a3 no picture but backlights

yikes... not good (if I see the post correctly). Are you using your glasses when you are seating the cables. The fact that things change so drastically leans toward something that you are doing. You are doing these cable moves with the tv unpowered... right?

I just messed with it again and am back to the red and black lines. I am seating the cables using a magnifying glass.

I tested the mosfit and get 15.6v on the top. 15.6v on the right bottom and 0v on the left bottom.

I was tapping on the tcon to panel ribbon on the offending side and it would flicker to get the whole vertical line red. Lost for now

[budwich]

Re: e701i-a3 no picture but backlights

I thought that too. I cleaned them and reseated them. Now I get this???

https://drive.google.com/file/d/1OQL...w?usp=drivesdk

yikes... not good (if I see the post correctly). Are you using your glasses when you are seating the cables. The fact that things change so drastically leans toward something that you are doing. You are doing these cable moves with the tv unpowered... right?

[suprteacher]

Re: e701i-a3 no picture but backlights

Wondering if it's a bad cable? Tried switching them around to see if it was a bad cable or bad panel on the bottom. Not sure if I screwed everything up by doing that.

[suprteacher]

Re: e701i-a3 no picture but backlights

I thought that too. I cleaned them and reseated them. Now I get this???

https://drive.google.com/file/d/1OQL...w?usp=drivesdk

[budwich]

Re: e701i-a3 no picture but backlights

that looks like one of the cable from the tcon to panel isn't set properly.

[suprteacher]

Re: e701i-a3 no picture but backlights

Hi guys-
I just fixed up a Vizio m701d-a3r. Same problem as the majority of others, left panel was bad.

I now have the middle of the screen with 2 huge vertical bars covering up. I will post a pic once I get down to the dungeon to take one. Curious as to whether this is bad tcon or bad bottom lcd?

Here are a couple pics.

[suprteacher]

Re: e701i-a3 no picture but backlights

Hi guys-
I just fixed up a Vizio m701d-a3r. Same problem as the majority of others, left panel was bad.

I now have the middle of the screen with 2 huge vertical bars covering up. I will post a pic once I get down to the dungeon to take one. Curious as to whether this is bad tcon or bad bottom lcd?

[Laguz75]

Re: e701i-a3 no picture but backlights

Followed Freakafter8 advice and it's alive!!!

[Badkiddy]

Re: e701i-a3 no picture but backlights

I had the same backlight no picture. I replaced the power supply and it's now all GOOD!

[nomoresonys]

Re: e701i-a3 no picture but backlights

Just want to say thanks to Freak and everyone else in this thread that has shared their knowledge and experience. Because of it I was able to get a Vizio M701d-A3R going again. I made a video showing the steps I took and tried to summarize what I've learned from the 49 pages of discussion here.

Here's my video if anyone is interested.
https://youtu.be/sJ0EzOuckyU

+10 Thanks Freakafter8 for figuring this fix out and saving these monsters from the landfill.