Technika L22/14A-GB-TCD-UK - sound but no backlight.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Greeno
    Member
    • Feb 2011
    • 36
    • Scotland

    #1

    Technika L22/14A-GB-TCD-UK - sound but no backlight.

    Hi

    These days, I would not normally bother even investigating a fault on a TV of this size, but I said I would take a look at it for a friend.

    It has sound but no backlight and I can see that the panel is working. No obvious visible failures but the fuse on the inverter board is open.

    The power supply is pretty basic – only outputs 12v and this seems to be good. It looks like this 12v is passed directly to the inverter via the main board.

    Other threads suggest that the CCFLs are an issue in these TVs - my question is: would a failed CCFL cause the inverter fuse to blow or is it more likely a problem with the inverter itself?

    Thanks for any advice.
    Attached Files

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
  • Ierwin
    Samsung UE60KU6079 backlight okay mainboard responsive, no picture, no sound
    by Ierwin
    Hello everyone,
    Ive got a UE60KU6079 on the workbench that is giving me some headaches trying to troubleshoot.
    The previous owner stated that there had been white dots on the screen which from the description sounded like some lenses fell of the backlight LEDs.
    He had opened the TV from the back, trying to get to the backlight, supposedly gave up, reassebled everything and gave the TV to me.
    I expected the worst like ripped COF cables or a cracked panel but could not find anything like that yet.
    Anyway I still fully expect that there has been something seriously damaged...
    05-13-2025, 03:31 PM
  • triplefour
    TCL 75S421 has sound but no backlight not even a flash
    by triplefour
    TCL 75S421
    PSU BOARD: 40-L402H8-PWD1CG
    it shows not even a flash of backlight when powering up.
    but the tv appeas to turn on and i can hear the sound of the menus moving and clicking. i can power down the tv with the button.
    testing the backlights with my tester all 4 strings lit up and showed similar voltage drops. around 110 or so.
    unplug mb and leave only psu plugged into backlights (PSU + BL SELF TEST MODE?) does not light the backlights.
    i do see 24v but 0v on PSON and BLON (i didnt write this down tho so cant be sure)
    with mb connected, PSON...
    11-17-2023, 09:54 PM
  • Attila Jamilov
    Which fuse is responsible for backlight on Lenovo Thinkpad T14 Gen 3
    by Attila Jamilov
    I upgraded display from HD to UHD recently, and I think I did everything right, battery was disabled in BIOS, and removed, yet the screen has no backlight. Both the old and new display behave the same way. I checked the motherboard and I see the fv1 fuse, and a fv2 spot for a fuse, but it's missing. Does anyone have any information on whether fv2 is responsible for backlight, or why it's missing? There's a schematic posted somewhere on this forum, but I can't view it as I don't have the hardware right now, since the laptop screen is broken and I run Linux.

    Also from further search...
    04-20-2025, 10:02 PM
  • ChaosLegionnaire
    what i went through dealing with my mobo with dead onboard sound!
    by ChaosLegionnaire
    so i took out one of my spare gigabyte ep35-ds3r mobos from storage for use to do some cpu, ram and video card testing of stuff i bought from ebay and got for free from momaka. he bought 50 e8400 cpus for cheap from ebay some years ago and i decided to help him relieve him of some of his supply since he had waaaay too many!! what did we say about hoarding too much stuff and depriving others of them?! *cough* socialism *cough* lol!

    i had to blow some dust off the board and heatsinks with the datavac as i didnt clean it up before putting it in storage. after finishing...
    09-13-2022, 09:02 AM
  • Loading...
  • No more items.
Working...