UN70NU6900FXZA Won't Boot Unless I Temporarily Disconnect Right LVDS Ribbon

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Scincidae
    New Member
    • Apr 2022
    • 2
    • USA

    #1

    UN70NU6900FXZA Won't Boot Unless I Temporarily Disconnect Right LVDS Ribbon

    I recently was given a UN70NU6900FXZA that would only boot loop once plugged in (auto powers on when plugged in). I found that disconnecting the lower (right side) LVDS ribbon, then plugging the TV in, followed by reconnecting the lower LVDS ribbon will allow the TV to work 100% normal as far as I can tell (no lines, no discoloration, no dimming or anything like that).

    I tried the tape method on the lower LVDS ribbon and found that if I cover pins 10 and 11 (counting from the bottom up) allows the TV to boot normal but 25% screen all the way to the right side is discolored. While trying the tape method I had covered many other pins 6-12 pins at a time and I could get it to boot without 10 and 11 being covered at the time so it's possible 10 and 11 are not the actual problem. Also disconnecting the other LVDS ribbon instead also stops the boot loop but it didn't boot up when I reconnected it, though it's possible that at the time I didn't seat it all the way or something.

    Maybe the main board is browning out at boot up for some reason and causing it to endlessly attempt to boot up but I have not been able to identify any bad/shorted components. I did borrow a thermal camera from work and looked around for any unusually hot components but nothing stood out. I looked for TVS diodes on the buffer boards that I read commonly fail but I could not find any.

    I've attached pictures of the main board and the covered pins for reference, if there are any other pictures that would help I will post them on request. Any suggestions are welcomed. Thank you.
    Attached Files
  • dskall
    Badcaps Legend
    • Oct 2016
    • 2905
    • usa

    #2
    Re: UN70NU6900FXZA Won't Boot Unless I Temporarily Disconnect Right LVDS Ribbon

    Usually you need to block traces on one side or the other. Center traces are data traces. You may also have a problem on t-con.
    I assume no responsibility for any stupid suggestions I might post.

    Comment

    • Jeryswan
      Member
      • Mar 2020
      • 39
      • USA

      #3
      Re: UN70NU6900FXZA Won't Boot Unless I Temporarily Disconnect Right LVDS Ribbon

      Originally posted by Scincidae
      I recently was given a UN70NU6900FXZA that would only boot loop once plugged in (auto powers on when plugged in). I found that disconnecting the lower (right side) LVDS ribbon, then plugging the TV in, followed by reconnecting the lower LVDS ribbon will allow the TV to work 100% normal as far as I can tell (no lines, no discoloration, no dimming or anything like that).

      I tried the tape method on the lower LVDS ribbon and found that if I cover pins 10 and 11 (counting from the bottom up) allows the TV to boot normal but 25% screen all the way to the right side is discolored. While trying the tape method I had covered many other pins 6-12 pins at a time and I could get it to boot without 10 and 11 being covered at the time so it's possible 10 and 11 are not the actual problem. Also disconnecting the other LVDS ribbon instead also stops the boot loop but it didn't boot up when I reconnected it, though it's possible that at the time I didn't seat it all the way or something.

      Maybe the main board is browning out at boot up for some reason and causing it to endlessly attempt to boot up but I have not been able to identify any bad/shorted components. I did borrow a thermal camera from work and looked around for any unusually hot components but nothing stood out. I looked for TVS diodes on the buffer boards that I read commonly fail but I could not find any.

      I've attached pictures of the main board and the covered pins for reference, if there are any other pictures that would help I will post them on request. Any suggestions are welcomed. Thank you.
      This solution worked for me. took all of like 5 minutes once i opened it. thanks man.

      Comment

      Related Topics

      Collapse

      • NolesFan
        Samsung un82ru88000f - Boot loop sort of but can correct with taping of LVDS ribbon
        by NolesFan
        Hello all... TV started boot looping. Opened the back panel and tried to isolate the problem. Just PSB no boot loop. PSB and MB no boot loop. Plug in the LVDS from panel to MB and boot looping starts up. It doesnt matter of order that I plug the LVDS ribbons back in, only 1 and no boot loop but as soon as 2nd one plugs in boot looping. I then noticed a flicker on the screen when I was closing the clip on the harness to the LVDS. Shut the lights off so I can see better, and I noticed as i slowly close it, I will get a picture, but as soon as it clips in, I lose picture and booting happens. So I...
        10-24-2024, 06:36 PM
      • privato89
        Nintendo Switch Oled HEG-001: Second-Stage Boot Failure
        by privato89
        Hello everyone,

        I'm facing an issue with a HEG-001 motherboard that is unable to complete the Second-Stage Boot. I'd like to start directly with my conclusion, which is the decision to replace the MAX77621AEWI chip, and understand if it could be a correct evaluation.

        Before I dive into the process that led me to this decision, I want to mention that I have a fully equipped lab where I can perform any kind of tests.

        Let's begin:

        Following some guides online, I tried to understand how the Boot phase of the Nintendo Switch works, and what are the...
        03-26-2024, 06:37 AM
      • alfredomfr1
        HP M32f FDH Monitor: 12v missing after connect the LVDS ribbon cable to the LCD circuit
        by alfredomfr1
        12v pin is shorted to ground in the LCD board (1st picture) if the LVDS cable is disconnected, 12v are OK in the Main Board (2nd Picture)
        06-04-2025, 10:23 AM
      • hinisa
        Xiaomi router freezes at boot after re-capping
        by hinisa
        I'm using Xiaomi Router 4A gigabit edition as wireless repeater. It worked fine for 2 years or so, but last week, wireless started to disappear.

        When I unplug/replug the power, it was working fine for a day/half a day or so until it freezes again.

        After testing with different power supply adapters and concluding it wasn't the issue I finally opened the case and this was the situation:



        Anyway I proceed to clean up the mess and replace all caps but unfortunately it made the situation worse. Now router can't even boot, either it freezes during...
        07-08-2023, 05:58 AM
      • Luke Anders
        Lenovo Legion 5 (15ACH6H/17ACH6H) - Does not boot into any OS
        by Luke Anders
        Hi everyone,

        A few details about the laptop itself:

        Name: Lenovo Legion 5
        Model: 15ACH6H (according to its back cover details) / 17ACH6H (according to the BIOS Menu)
        BIOS Version: GKCN60WW
        EC Version: GKEC65WW
        Serial Number: PF39AQ7Z
        Board Model: NM-D562 Rev 3.0
        RAM: 16GB Installed, DDR4 (brand new)
        NVME: 500GB NVME drive (brand new, installed Windows 10 onto it for testing purposes and tested on another laptop (a dell XPS) works perfectly fine and boots in)

        I bought this laptop recently from eBay as a faulty device....
        10-12-2024, 05:13 AM
      • Loading...
      • No more items.
      Working...