TCL 65S4 Backlight Troubleshooting

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • thelug
    New Member
    • Apr 2021
    • 3
    • USA

    #1

    TCL 65S4 Backlight Troubleshooting

    Good afternoon, I have a TCL Roku TV 65S4 with a service number of 65S4TDAA. I searched and didn't find any posts about this TV.
    Device was working properly no issues. One day screen randomly went black. I noticed ghosting symptoms of the back light being out. I power cycled and was doing some troubleshooting and it turned back on and was fine for 6+ months. It went out again last week and won't turn back on like it did the first time. Sound and picture as expected, just no back light. I have tried the reset and power drain steps. If I fully drain the power when unplugged, when it is powered back up it will power the backlight and the TCL logo shows and appears to work then immediately (less than 2 seconds) the lights turn back off. I got a known working power supply board from another TV and tried swapping it and the symptoms are still the same. Since the sound and picture still work, I don't believe it is a TCONN board, but since the lights turn on after a power cycle, I am hesitant to think it is the back lights themselves, but I am a computer guy not a TV guy. I am comfortable with boards and ribbon cables etc, I have replaced TCONN and power boards before successful, but this is my first possible bad backlight and wanted to know the best troubleshooting steps since the light turn on for a moment then off. Any help would be greatly appreciated.
  • neilc6
    Badcaps Legend
    • Nov 2015
    • 1550
    • Canada

    #2
    Re: TCL 65S4 Backlight Troubleshooting

    Backlight issues are almost always caused by bad backlights. Protection circuitry is kicking in to shut them down because an error is detected. https://techhometravel.com/lg-ln-ser...ed-backlights/

    Comment

    • thelug
      New Member
      • Apr 2021
      • 3
      • USA

      #3
      Re: TCL 65S4 Backlight Troubleshooting

      Originally posted by neilc6
      Backlight issues are almost always caused by bad backlights. Protection circuitry is kicking in to shut them down because an error is detected. https://techhometravel.com/lg-ln-ser...ed-backlights/
      Thanks for the info... So that is LG specific and also mentions the Samsung and a few others. Is it similar for the TCL? Can I find a repair / disassembly guide for my TCL version? I see mixed info on if it's worth replacing on bigger TVs.

      Comment

      • neilc6
        Badcaps Legend
        • Nov 2015
        • 1550
        • Canada

        #4
        Re: TCL 65S4 Backlight Troubleshooting

        Very difficult to disassemble a 65 inch panel without damaging it. Suction cups may help. All tvs are very similar. Differences will be if screws are used versus clips and if double sided tape is used. You may find a video for TCL models if you search.

        Comment

        • JohnyRuffneck
          New Member
          • Apr 2022
          • 2
          • America

          #5
          Re: TCL 65S4 Backlight Troubleshooting

          Hello there,
          I'm dealing with the same situation myself , I'm wondering if you had luck with it.

          Comment

          • Storyteller12
            Badcaps Veteran
            • Jun 2020
            • 624
            • USA

            #6
            Re: TCL 65S4 Backlight Troubleshooting

            I just replaced the backlights in this model. It’s definitely the backlights causing your issue.
            The screen is difficult to get out since they used double sided tape. Have to be careful not to break the screen removing it.

            Other than that it’s straight forward backlight repair.

            Comment

            Related Topics

            Collapse

            • triplefour
              UN65TU700DF picture and sound but no backlight. BL tests ok but repl. PSU didnt fix!
              by triplefour
              this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
              i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
              unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
              according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even...
              09-13-2023, 10:43 PM
            • Comp_Pro
              No Backlight Macbook A1990 820-01041
              by Comp_Pro
              Hello all,

              Am trying to figure out this backlight issue with this A1990 Macbook Pro.

              Tests performed:

              There is no backlight even with a good screen.
              Backlight IC is receiving the correct support voltages.
              Fuse F8400 ok
              Current sense resistor R8400 ok
              Backlight IC is receiving 3.3V on enable pin.
              Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
              Backlight IC receiving 5V from PP5V_G3S
              Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
              I2C_BKLT_SCL and I2C_BKLT_SDA both measure...
              05-06-2024, 10:23 PM
            • canadaboy25
              LG Flatron 24EN33TA No Backlight When Cold
              by canadaboy25
              Hi all,

              I've got an LG Flatron 24EN33TA with a backlight issue. The problem began with the monitor not powering up after sitting for a long time (overnight or during the day throughout work). When I would wake the computer up, the backlight would flick on for a second then go out. Sometimes it would take many tries to get it to come on. Once the monitor came on, it worked flawlessly until another long duration of being powered off.

              I thought the problem would be bad caps but I checked both of the caps on the board and they are fine. I also tried powering the monitor from...
              03-07-2023, 12:23 AM
            • Document Archive
              HP ProDesk 600 G5 + APC Back-UPS 700VA ProDesk 600 i5-9500 Specification for Upgrade or Repair
              by Document Archive
              This specification for the HP ProDesk 600 G5 + APC Back-UPS 700VA can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the ProDesk 600 G5 + APC Back-UPS 700VA boardview and ProDesk 600 G5 + APC Back-UPS 700VA schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties...
              09-12-2024, 02:30 PM
            • Document Archive
              HP ProDesk 600 G5 + APC Back-UPS 700VA ProDesk 600 i7-9700 Specification for Upgrade or Repair
              by Document Archive
              This specification for the HP ProDesk 600 G5 + APC Back-UPS 700VA can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the ProDesk 600 G5 + APC Back-UPS 700VA boardview and ProDesk 600 G5 + APC Back-UPS 700VA schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties...
              09-12-2024, 02:30 PM
            • Loading...
            • No more items.
            Working...