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    Re: e701i-a3 no picture but backlights

    Okay so I have no good news to report, but it may not all be bad news.

    I inspected both sides of the drivers and none of the connectors looked burned out or brown or anything, but I know they might not always appear burnt out so this doesn't really tell me too much.

    I put in the used t-con I got off ebay and got no picture with either of the sides disconnected, just the same backlit screen with no picture. I tried just connecting both sided and turning the tv on just to see and still nothing. This leads to me believe I might have just gotten a bad t-con - I got my hands on a multimeter so I'm going to try testing to see if that's the issue.

    If it turns out that this t-con isn't bad, then the only other thing I can think of is that somehow the screen or the t-con isn't being correctly powered, and that's why I'm not getting picture regardless of what ribbons are plugged in. But then I'm back at square 1 and I have to figure out what needs to be fixed. Maybe I'll get lucky and it's nothing too severe, or maybe this thing's a lost cause.

    If anyone's got any advice it'd be greatly appreciated. Thanks again!

    Comment


      Re: e701i-a3 no picture but backlights

      Here is my post form before... you may not have a bad tcon board... it may be something else ... in the youtube vides it will tell you wat to measure to verify if the tcon is bad... also in the other video to see what side is bad too if it is the drivers


      OKAY got the TV going to dig into it tomorrow and test some resistances on the TCON board.

      SYMPTOMS- has back light, no image, 2 or 3 bright white spots at the bottom

      I found these videos:

      How to test Mosfet:
      https://youtu.be/yTnkOfwBGGE

      How to tell you how to determine which side of the panel is bad:
      https://www.youtube.com/watch?v=cyCKoMi_5IA

      How to remove the Ribbon:
      https://www.youtube.com/watch?v=sJ0EzOuckyU




      Originally posted by gimmedatpretzel View Post
      Okay so I have no good news to report, but it may not all be bad news.

      I inspected both sides of the drivers and none of the connectors looked burned out or brown or anything, but I know they might not always appear burnt out so this doesn't really tell me too much.

      I put in the used t-con I got off ebay and got no picture with either of the sides disconnected, just the same backlit screen with no picture. I tried just connecting both sided and turning the tv on just to see and still nothing. This leads to me believe I might have just gotten a bad t-con - I got my hands on a multimeter so I'm going to try testing to see if that's the issue.

      If it turns out that this t-con isn't bad, then the only other thing I can think of is that somehow the screen or the t-con isn't being correctly powered, and that's why I'm not getting picture regardless of what ribbons are plugged in. But then I'm back at square 1 and I have to figure out what needs to be fixed. Maybe I'll get lucky and it's nothing too severe, or maybe this thing's a lost cause.

      If anyone's got any advice it'd be greatly appreciated. Thanks again!

      Comment


        Re: e701i-a3 no picture but backlights

        Well what was tested? people usually start with testing the voltages at the connector on the powerboard with the cables all hooked up, it's the connector that the cable from powerboard to mainboard hooks into, most times there's a legend/map nearby that gives the expected voltages, you measure them with your mutimeter, set meter to 20 vdc then report them, put neg probe on chassis metal ground, pos probe on pin of connector, measure in standby take note, leave probes where they are then power on tv and again take note of voltages, report them here, example pin 1-ps-on-0 volts standby-power on-3.3 volts.
        Last edited by nomoresonys; 10-25-2020, 07:41 AM.

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          Re: e701i-a3 no picture but backlights

          A video is worth a thousand words...if you already know this then maybe it will help someone else: https://www.youtube.com/watch?v=4v8DcqCNG4A

          Comment


            Re: e701i-a3 no picture but backlights

            Thanks for the responses guys! I tested the voltages following a few different videos/guides and was able to determine that

            A) my t-con is being powered as it should be and all my other voltages seem to be good
            B) both the t-cons that I have now are duds. I don't know if used one I bought was broken when I got it or if I accidentally blew it. But I only powered the TV on with one side of the ribbons disconnected so theoretically I shouldn't have blown it. And when I powered on the TV I didn't get the "3 seconds of picture and then fade to black" - I just got nothing, same as my original busted one.

            I didn't know there was a way to test which side of the panel was bad without turning the TV on/risking the T-con so that video you posted is extremely helpful. I ordered another T-con that should be here in a few days so I'll make sure to run those tests beforehand to see if I can narrow down the problem.

            Will check back in in a few days

            Comment


              Re: e701i-a3 no picture but backlights

              Well I'm pretty much at the end of the line on this one.

              I determined which side of the panel was bad using the video sent above(https://www.youtube.com/watch?v=cyCKoMi_5IA). The video says that if the panel is good then you should get 9 to 10 kohms so here's a summary of the tests I did:
              1. Removed the left ribbon cable (going directly to the t-con) and got 1kohm
              2. Reconnected the left and removed the right side and got 9kohm (which, unless I'm misinterpreting the video, means the left side is good and the problem is the right side)
              3. Reconnected the right main ribbon cable and disconnected the right side ribbon cable (the one going to the side drivers, not the one going directly to the T-con as shown in that video) and got 9kohm.

              So that would mean that the right side drivers are the ones that went bad so I left that disconnected. Then I plugged the TV in and turned it on and still got 0 picture. Then I tried checking the voltages on the new T-con board it's looking like this third T-con is now somehow blown (and this one was new, not used).

              I have one more T-con to try - it's slightly different model number but it's supposed to be compatible, I think it came out of a similar era sony TV that was less prone to blow like the vizio one was (someone mentioned that you could use these earlier on in the thread).

              I don't know what else I can really try in terms of troubleshooting so I guess I'll just put this one in and let it rip. Then if that doesn't work, I can try the irreversible removal of the right side drivers as a last ditch hail mary, but if those drivers aren't already being powered then I don't know how much of a difference it will make.

              Unless anyone has any further suggestions or ideas? But at this point I might just buy myself a new TV and keep this as a side project to come back to.

              As always thanks for your help, cheers

              Comment


                Re: e701i-a3 no picture but backlights

                Minor update: I put in the new new T-con board, like I said this one is slightly different but it was easy to identify the appropriate components on it, so I ran every test I could without plugging the TV in/turning it on:

                I have the right side ribbon cable disconnected and I'm getting between 9-10 kohm (which according to https://www.youtube.com/watch?v=cyCKoMi_5IA is the correct reading from the panel)
                I ran the diode/continuity tests shown in the shopjimmy video (https://www.youtube.com/watch?v=yTnkOfwBGGE) and got the .42 and OL readings, indicate that the board itself is good

                Is there anything else I should test before turning the TV on? Would just preemptively ripping the right side drivers off potentially give me a different outcome than just having it disconnected? I know that's irreversible so I might not do that unless it actually would make a difference.

                I could also potentially disconnect the main ribbon cable that goes directly to the t-con rather than just the one on the side, but I believe that's what I tried last time and still had no luck.

                Going to leave it alone for the night and pick back up tomorrow before doing anything.

                Comment


                  Re: e701i-a3 no picture but backlights

                  Okay so I disconnected the right side drivers, but still got no picture.

                  However, when I disconnect the right/main ribbon cable (the larger one that goes directly to the T-con), I'm able to get picture on the left side of the screen, while the right side just stays blank (which makes sense because both the vertical and side drivers are disconnected at this point).

                  I'm not sure why this would be happening, since most people seem to get full picture that's just dimmed on the bad side when the side drivers are disconnected.

                  I still haven't physically removed the side drivers, but I figure at this point I don't have much else to lose. But it's odd that I can't get any picture on the ride side of the screen anymore, even with the side drivers disconnected. I have a feeling that the vertical drivers on the right side may be toast as well, or potentially the large ribbon cable itself somehow went bad? If it's the vertical drivers then I know for sure the panel is garbage, so I guess I'll take the right side drivers off and see where that gets me.

                  Comment


                    Re: e701i-a3 no picture but backlights

                    I would like to announce that, thanks to this post and its commenters, I have successfully repaired the tv (e701i-a3) as of last night. So thank you all.

                    Comment


                      Re: e701i-a3 no picture but backlights

                      This thread was a long read, but worth it. I had a Vizio E70-E3 that did have multiple backlight LEDs burnt out and some underrated capacitors. After getting the backlights working, I was sad to see the image was distorted with odd lines. It actually started with both reddish vertical lines and intermittent horizontal white thin and thick lines. Sometimes it would show a whole image and other times it would have a dark blob on the bottom right corner with white lines. I was about to give it up for parts, then came across this thread. This TV is 70 inches, with no driver boards on the side of the panel. As a last ditch effort, I peeled off the tabs along the one bad side of the panel, reseated all other connectors and the picture looks fine. Amazed.

                      Comment


                        Re: e701i-a3 no picture but backlights

                        Originally posted by xDavidxPaynex View Post
                        I would like to announce that, thanks to this post and its commenters, I have successfully repaired the tv (e701i-a3) as of last night. So thank you all.
                        What did you have to do to fix your problem?
                        Signature:Seemingly hopeless tv fixer

                        Comment


                          Re: e701i-a3 no picture but backlights

                          I'd like to add some things to this thread if I may. I've probably done at least 20 of these horizontal drive board removals by now and I'm not sure if these things were covered, but just in case:

                          I just did this procedure on a Sharp model LC-70LE757U 70" 3D tv.

                          Symptoms:

                          TV will not turn on
                          "Icon" light (the upside down "V") flashes code 24 and/or 25

                          Diagnostic actions taken:

                          From screen to T-Con board there are 4 flat flex cables on this model. Detach right outboard flat flex cable (when looking at the BACK of the TV) and try to power on TV, TV powers on with darker image along with a horizontal line and bar emanating from the left side of the screen (when looking at the FRONT of the TV) where the #2 COF tab (from the bottom of the screen) is located.

                          The horizontal line and bar emanating from the left side of the screen (when looking at the FRONT of the TV) mostly disappears about 3/4 of the way to the right side of the screen (when looking at the FRONT of the TV)

                          Inspect #2 COF (Chip On Flex) tab from the bottom of the screen. The green tab is discolored to brown in color in the area surrounding the Gate Driver IC. The IC itself does not appear to be discolored.

                          Repair (WORK AROUND) action taken:

                          Remove BOTH left side (when looking at the FRONT of the TV) horizontal drive boards by peeling the attached COF tabs FROM THE SCREEN.

                          CHECK ALL COF TAB ATTACHMENT POINTS AT THE SCREEN to be sure they PEELED OFF CLEANLY since remaining adhesive or traces of the COF tabs can cause problems.

                          Re-attach right outer flat flex cable (when looking at the BACK of the TV) to t-con board and power on TV.

                          Verify there are NO THIN HORIZONTAL LINES emanating from the left side of the screen (when looking at the FRONT of the TV). None present.

                          Test TV for no less than EIGHT HOURS before re-assembly.

                          Top take-aways:

                          1) The horizontal drive boards and any components attached ARE NEVER the source of this problem. It is ALWAYS an overheated/shorted GATE DRIVER IC embedded in the green flex cable that causes this problem.

                          2) BEFORE REMOVING THE HORIZONTAL DRIVER BOARDS it is IMPERATIVE one CHECKS EACH GATE DRIVER IC for discoloration ON THE IC ITSELF and on the FLEX CABLE surrounding the embedded chip. A severely damaged GATE DRIVER IC will often be blue in color and not have a shiny chrome appearance as it should. Extreme overheating of the GDIC will often cause a blue in to white color appearance upon the chip itself. The green flex tab will often have brown discoloration surrounding the GDIC and the flex tab will be distorted (wrinkled) around the IC. The flex tab may have holes in it and the brown discoloration may follow several of the traces leading up to or away from the GDIC. If none of these are found, check the flex tabs/GDICs on the OTHER SIDE OF THE SCREEN before removing the horizontal drive boards.

                          3) Remove the horizontal drive boards WITH THE FLEX CABLES from the screen. NEVER leave the flex cables attached to the screen.

                          4) MAKE SURE THE FLEX TABS PEELED FROM THE SCREEN CLEANLY! AFTER REMOVAL LOOK AT THE CONNECTION POINTS (TRACES) ON THE FLEX CABLES WHERE THEY WERE ATTACHED TO THE SCREEN to ensure ALL OF THE TRACES PEELED AWAY WITH THE FLEX TAB!!!!!!! Furthermore MAKE SURE NONE OF THE BONDING ADHESIVE REMAINS UPON THE SCREEN. I like to heat the bonded connection slightly with a hair dryer to no more than 120 degrees F to help the flex tabs peel away cleanly.

                          5) CAREFULLY INSPECT THE PICTURE on the side the horizontal driver boards were detached from. IF THERE ARE THIN LINES EMANATING FROM THE LEFT SIDE OF THE SCREEN this means the flex tabs DID NOT PEEL AWAY CLEANLY! This can lead to problems later.

                          6) THIS PROCEDURE IS NOT A REPAIR. IT IS A WORK-AROUND RESCUE PROCEDURE TO ELIMINATE A SCREEN SHORT WITH THE INTENTION OF EXTENDING THE LIFE OF THE TV!!!!!!!

                          7) Severely shorted/overheated GDICs can place stress upon the components of the source driver boards (vertical drive boards), the other horizontal drive board and all of their gate driver ICS. It can take 30 days or more before you know if this procedure rescued the TV.

                          8) if there are ANY PICTURE PROBLEMS after applying the rescue procedure the TV should be considered totaled and it be recycled!

                          9) I have NEVER encountered a right side (when looking at the FRONT of the TV) GDIC failure. It has ALWAYS been the left side (when looking at the FRONT of the TV) that has failed. This isn't to say the right side GDICs never fail, just my experience.

                          After doing several of these procedures this is what works for me.
                          Attached Files
                          They call me......."threadkiller"

                          Comment


                            Re: e701i-a3 no picture but backlights

                            Originally posted by freakaftr8 View Post
                            Use a sot-23 mosfet labeled QF as equivalent. You can get them in the us. N channel 2 amp 45v.

                            Hi, I was wondering if you could recommend the actual component & supplier. I have checked with the more popular suppliers (Digikey, Mouser & Newark) and found something close but not exactly what you spec'd out. I recently acquired a Vixio e601i with a t-con that has this transistor fault.

                            thanks,
                            rich

                            Comment


                              Re: e701i-a3 no picture but backlights

                              Thanks to this board I sucessfully revived my Vizio E701i-A3E. Same simptoms- backlight with no picture. Ordered a new T-con board from Encompass and removed the side driver ribbons. Found Left side was bad, ripped off the Drivers and reassembled. TV works great, although the early version of smart apps in this TV are laughable now. Got the TV for free, T-con board was my only investment.

                              Thanks freakaftr8!

                              Comment


                                Re: e701i-a3 no picture but backlights

                                Thanks to all 3 of you after a long battle with a free tv I got a year and a half ago but berely tinkered with I was able to sit down and go through 10 pages before I realized there's a 3/4 ribbon on each side… smh well time to remove the board and put this thing back together. Thanks to all I'll upload another pic once I uninstall the driver board, I hope you can add another one to the list, although I'm about 6 years late…
                                Attached Files

                                Comment


                                  Re: e701i-a3 no picture but backlights

                                  Originally posted by 12jmorin View Post
                                  Thanks to all 3 of you after a long battle with a free tv I got a year and a half ago but berely tinkered with I was able to sit down and go through 10 pages before I realized there's a 3/4 ribbon on each side… smh well time to remove the board and put this thing back together. Thanks to all I'll upload another pic once I uninstall the driver board, I hope you can add another one to the list, although I'm about 6 years late…
                                  I am one happy dude. Y'all are geniuses!
                                  Attached Files

                                  Comment


                                    Re: e701i-a3 no picture but backlights

                                    @freakafter8, I owe you a meal, so if you send me your paypal or whatever I'd be happy to send you some cash.

                                    I've had my 70" Visio since November of 2013 when I got it from the local Tiger Direct store. It's been a great TV and when it stopped showing a picture randomly a few days ago, I figured the Xbox froze. Instinctively, I held down the Xbox button to reset the system and then turned everything off since I needed a break anyway. Later in the evening I turned the set back on to watch TV and there was still no picture. I could see the backlight, but I didn't know about audio since I run the audio through a receiver and the TV speakers are always all the way down. Anyway, I spent like 3 hours researching the issue, reading your thread, etc. Finally today, I took the TV apart, and disconnect the right side 1/4 ribbon cable because I knew there had been a very faint dark spot, and maybe 2 or 3 pixels out after the last 8 years on that side. I turned the set on and there was a picture. Slightly distorted, but it was there. I peeled off all the ribbon things to the screen, and the TV was working like I remembered. I put it back together, turned everything on, and I can't see any difference as of yet. Hopefully the refresh rate won't affect me gaming, but I don't think my Xbox is running 120Ghz anyway. I didn't see any burned spots on my ribbon, but maybe I'm missing something. Thanks so much!
                                    Attached Files

                                    Comment


                                      Re: e701i-a3 no picture but backlights

                                      Just read all this again.

                                      Just a quick question please?

                                      I already have a thread here https://www.badcaps.net/forum/showthread.php?t=95273

                                      I wonder if I just remove the side display boards or board on mine, may it meet with some success, or do I just consign it for the sale of parts?

                                      Great to see some here meeting with success.
                                      Signature:Seemingly hopeless tv fixer

                                      Comment


                                        Re: e701i-a3 no picture but backlights

                                        @freakafter8...
                                        On the first page, post number 3,you showed us 8 pictures of your work.

                                        Picture 20150913_151230.jpg (3 of 9) shows the edge boards taken off the panel, with what I presume (?) is the brown bonded tape that goes to the panel.

                                        How did you remove them, and reattach them please?

                                        The reason I ask, is that I am trying to determine if any of my smd's are not working right, in this thread, but it means surgery would have to take place with the boards still attached? Your faults here, sound similar to my thread, and I am trying to solve my woes too.

                                        https://www.badcaps.net/forum/showthread.php?t=95273

                                        Thank you
                                        Signature:Seemingly hopeless tv fixer

                                        Comment


                                          Re: e701i-a3 no picture but backlights

                                          He pulled them off and once off they don't go back on.

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