Schematics & Help Needed. No Backlight Voltage

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • claudyu07
    Claudyu07
    • May 2014
    • 125
    • Ireland
    #1

    Schematics & Help Needed. No Backlight Voltage

    hi Guys. i have this tv here with power board LEKE LKP-SP017 REV:0.5 and i can't find schematics at all.

    Tv switch on and working fine but no backlight.
    No +24V on power board for inverter.

    I have switched on TV, disconnected +24v cables from power board and used external power supply with 24V for inverter and all working fine.

    Thanks very much.
    Attached Files
    Tags: None
    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA
      #2
      Re: Schematics & Help Needed. No Backlight Voltage

      Make and model of the TV?
      What control signals (PS-ON, BL-ON, etc.) do you have feeding the power supply board?
      We also need to see the whole back side of the TV to see how all the boards are connected together.
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

        Comment

        Previous template Next

        Related Topics

        Collapse
        • Tynan Dill
          Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
          by Tynan Dill
          I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

          Upon bringing it home and plugging it up, it showed a standby light.

          I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

          The screen seems to blackout and stay black, but with a flashlight I can see the display.

          With my Playstation 4 connected via HDMI, and running a game I can hear sound.

          Assuming...
          ORIGINAL POWER SUPPLY BOARD
          7 Photos
          11-22-2024, 01:46 PM
        • rattlesnake
          Voltage issues SY-5SSM, where's the problem? Help needed
          by rattlesnake
          Hello everyone,

          I'm trying to fix this SY-5SSM motherboard (Socket 7).



          When the PSU is connected it powers on by itself but there's nothing on the POST card, no beeps.
          The BIOS EEPROM is ok (latest BIOS was flashed).
          All the jumpers are set ok.
          All the 1000µF 6.3v (14) and 1500µF 16v (2) caps are in spec.
          There are two 76129D MOSFETs (datasheet). I took them out and tested them and they are ok (no continuity from drain to source) in off state.
          But the voltage in the gate of the second 76129D fluctuates between 1.468-1.649,...
          01-26-2025, 11:26 AM
        • DanPoka
          Guide me through repairing a Dell p2210f LCD ccfl backlight monitor
          by DanPoka
          I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
          Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
          This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered...
          02-15-2025, 05:05 AM
        • Fernon@Repair
          Gigabyte Z490 Gaming X Motherboard No VCORE Voltage
          by Fernon@Repair
          i have Gigabyte Z490 Gaming X Motherboard .it has a power on no display fault .. no vcore voltage and debug led stuck CPU LED .

          VCCIO voltage ok
          VCCSA Voltage OK
          VCCPLL Voltage OK
          Ram Voltage ok
          RamVTT OK
          VPP 2.5 OK

          But No Core Voltage

          and i want to this vrm ic datasheet or pinout (ISL69269)
          anyone have this ic pinout voltages?...
          06-25-2025, 07:19 AM
        • cheebster
          iPad Pro 12.9 5th Gen Backlight Issue
          by cheebster
          Hello, got an iPad Pro A2378 12.9 5th gen with no backlight. Got another test unit without screen, tested the screen, still no backlight with the test unit.
          Figured out the backlight on the screen was bad, ordred a new backlight from mobilesentrix, *carefully replaced it* without damaging the lcd, oh well.
          Final result, issue is still there, the screen has no back lights. So i'm back to square one, with 3 hours less and 100$ out, issue still on the screen.
          The panel is still ok, i can see the apple in the middle of the screen when it kicks in, just no backlight.
          Anyone...
          05-20-2025, 09:17 AM
        • Loading...
        • No more items.
        Working...