General - Backlight LEDs Q.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • stav242
    Senior Member
    • Jan 2014
    • 61
    • United Kingdom

    #1

    General - Backlight LEDs Q.

    I have a single faulty LED on a backlight strip of this Technika 32" 32F21B-FHD TV.

    as a bit of a trial, i thought i would try stacking a salvaged LEDs cut out from other scrap TVs - but it seems the LED brightness and colour vary on the others... and with the diffuser back on its quite noticable that the new LED is not the same as the others, too bright or blue tint.

    is there any info out there on what SMD LED types are used on specific models - or how to identify the SMD LED part code easily. ?

    in the long run, i would rather replace the SMD LED on the strip for 50p than have to fork out £20 a time for a complete new strip. - often more than the 32" Tv is worth.
    i replaced one as a test, fiddly, but possible.

    i found this post but only discusses the size related to the product number (which is helpfull)
    https://www.badcaps.net/forum/showth...hlight=SMD+LED

    - alternatively, the SMD LED rolls of 100 are about £6 - i could always buy a few different types and try my luck...
    Last edited by stav242; 01-05-2022, 03:54 AM.
  • diif
    Badcaps Legend
    • Feb 2014
    • 6978
    • England

    #2
    Re: General - Backlight LEDs Q.

    Trial and error or a spectrometer. Whilst it is cheaper to replace single LEDS, all of them will have the same life, if you're selling these with warranty, there is a very good chance they will return.

    Comment

    • ducky29
      Badcaps Veteran
      • Dec 2015
      • 370
      • Europe

      #3
      Re: General - Backlight LEDs Q.

      You will waste a lot of time and patience if you choose to remove the lens, replace led, glue back the lens. You will need at least 2-3 hours from start to finish.
      Also packages are different, there are 3528 3030 3volts, 6volts, etc etc, you might find it difficult to find the correct replacement.

      I bought this https://www.aliexpress.com/item/32474591848.html for 10$ in 2017 and I have only used about 50 on clients who would only have 1 or 2 faulty leds and would not accept the qoute for full array.If you have the same led as I listed above I can send you as much as you want as long as you pay for shipping.
      I don't think its worth your time. Based on my experience it better to replace the whole set and you are good to go for at least 2-3 years.
      But its up to you, if you have the time and skills to do it then go ahead!

      Comment

      • stav242
        Senior Member
        • Jan 2014
        • 61
        • United Kingdom

        #4
        Re: General - Backlight LEDs Q.

        im just doing it for a hobby... so happy to spend more time on it and keep the costs down.

        i found a ebay seller who quotes the SMD LED types suitable for particular manufacturers... a bit closer than guessing..

        https://www.ebay.co.uk/sch/tvrepairledtester

        eg..

        100pcs 3528 2835 3535 8520 7020 SMD Lamp Beads For LG LED TV Repair
        100Pcs 3537 3535 2828 3228 5630 7032 SMD Lamp Beads for Samsung LED TV Repair
        100Pcs 7020 SMD LED Lamp Beads 6V For Philips Skyworth LED TV Strip Repair

        Comment

        • alfatv
          Badcaps Veteran
          • Sep 2020
          • 353
          • Canada

          #5
          Re: General - Backlight LEDs Q.

          Originally posted by stav242

          as a bit of a trial, i thought i would try stacking a salvaged LEDs cut out from other scrap TVs - but it seems the LED brightness and colour vary on the others... and with the diffuser back on its quite noticable that the new LED is not the same as the others, too bright or blue tint.
          This is doable, you need to get LED tester, then compare original and target LED for voltage, current and color.
          Another check is for LED size and footprint.
          Also often worn out LED's are blueish and don't match original color.

          Comment

          • stav242
            Senior Member
            • Jan 2014
            • 61
            • United Kingdom

            #6
            Re: General - Backlight LEDs Q.

            Update.
            Ordered some 3030 and some 3528s.

            Tested existing led current on both the new ones compared to existing

            and used a simple Lux metre all on my phone to guage brightness...

            Using both current and lux, it was enough to match up a replacement 3528 led to the existing ones on the strip.

            Much cheaper and more sustainable then replacing the while strip.

            Comment

            • neilc6
              Badcaps Legend
              • Nov 2015
              • 1550
              • Canada

              #7
              Re: General - Backlight LEDs Q.

              LED failures aren't random. They wear and have limited life just like light bulbs. Replacing single LEDs isn't worth it since the remaining LEDs will eventually fail. I had two TVs recently come back which were repaired with used strips and the backlights turned down. One came back in about 8 months (owner couldn't wait for new strips so I replaced with used and ordered new strips for him to hold onto - LG 42LN) and second came back shy of 2 yrs (Sharp 50LB). Don't bother with RCAs any more since they have low resale value and can't get new strips.
              Last edited by neilc6; 01-10-2022, 02:44 PM.

              Comment

              • jimbofz
                Badcaps Veteran
                • Apr 2013
                • 537
                • uk

                #8
                Re: General - Backlight LEDs Q.

                any idea why sharp leds have 10 volts across them not 3v or 6v?
                model LC40LE600E

                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
                • hollox123
                  ASUS ROG Strix G713QR - Keyboard, backlight and side LEDs don't work
                  by hollox123
                  Hello, I have an "ASUS ROG Strix G713QR" laptop, and for approx. 3 months I have the following problems:

                  1. Laptop keyboard doesn't work
                  2. The backlight on the laptop keyboard doesn't work
                  3. The x2 side LEDs (red) on the laptop don't work

                  The power button works, the touchpad works, and all the USB, HDMI, Ethernet, etc. ports work.

                  I already tried to reinstall all the drivers and reinstall Windows. So I don't know what to try anymore that is software-related.

                  But I am strongly aiming that it is somehow a BIOS-related problem,...
                  05-11-2025, 08:05 AM
                • signal.quest
                  Panasonic LED TV TC-40A420U - Replaced Backlight LEDs but now no image/display or garbled
                  by signal.quest
                  I have a Panasonic LED TV TC-40A420U. The TV was given to me as an attempt to fix or throw out. I replaced the Backlight LEDs and now the screen lights up, but there is no image/display. If I play with the up/down buttons I can get the display to change from black to garbled. I can't get sound from HDMI but not sure of what input is selected. I have no remote control. When I connect a laptop to the HDMI ports it recognizes a Panasonic TV for display and sound output but I can't see or hear anything through the TV. This makes me think the mainboard is OK, but not sure if mainboard can...
                  03-17-2024, 10:14 AM
                • howardc64
                  A1312 (27” iMac 2009-2011) A1407 (Thunderbolt Display) A1316 (Cinema Display) Display Black Screen Repair
                  by howardc64
                  Problem

                  This is an LG edge LED lit LCD Display. The LEDs are on the bottom edge of the display. There are 2 bars (left and right) Each bar has many LEDs and a 6 pin connector. Each pin drive several LEDs thus is the highest current flow / heat junction. The weak lead free solder gradually fails with thermal expansion/contraction cycling and increases resistance. PSU will compensate up to a point, then when the current is too high, PSU just shut down the backlight causing a dark display. I have even seen one which the connector just fell off as solder points became completely detached....
                  08-04-2024, 10:36 PM
                • tmhobadcap
                  TCL 65S403 Backlight LED Question
                  by tmhobadcap
                  I got the TV from a friend. He claims that no image but sound from the TV.
                  I confirmed that when shine a flashlight on to the screen, I can see the image. And this should be backlight problem.
                  I open up the TV and found a few leds failed. And now I am ordering a new set of backlight strips for it.

                  But there is something that I do not understand when checking the leds. I do not have an led tester. I only use a bench power supply. I first set the voltage to 3V and current to 10mA. I could not light up the led until I increase the voltage to 12V. I understand most...
                  05-25-2025, 11:03 AM
                • Loading...
                • No more items.
                Working...