Smd led types

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • angelos
    Badcaps Veteran
    • Dec 2012
    • 563
    • South Africa

    #1

    Smd led types

    Good day all,
    I did some research on this topic but i cannot get suitable information. Is there a comprehensive web site that has information on SMD LED datasheets.
    For example, i have backlight failure on a tv and order the exact same edgelit strip then when i put them in the set and start up the power supply shuts them down immediately. If i fix the old strips then it works fine. If i use a LED tester then if i power a segment (4 x 12) the tester voltage settles down on 40.4V (original) and the replacement strip (44.4V). So that should mean that their forward currents differ. I guess its impossible to know what LEDS the supplier of the back lights used. Communication with chinese suppliers is non existent on aliexpress.
  • diif
    Badcaps Legend
    • Feb 2014
    • 6978
    • England

    #2
    Re: Smd led types

    LEDs are either 3v or 6v. I compare their look under a microscope and the light they give off with a spectrometer. There are data sheets for smd LEDs but with no way of identifying what LED is on what strip they seem pretty pointless IMO.

    Comment

    • angelos
      Badcaps Veteran
      • Dec 2012
      • 563
      • South Africa

      #3
      Re: Smd led types

      So why are the chinese replacement leds causing the power supply to trip whereas the original is not doing that? Also when i connect my LED tester there is a difference between the two strips. The tester drive voltage is slightly different between the original and replacement.

      Comment

      • diif
        Badcaps Legend
        • Feb 2014
        • 6978
        • England

        #4
        Re: Smd led types

        Unless it's one of the latest LED testers that outputs 300mA it is just a quick test tool carrying out a part test. LEDs need the correct voltage and current if you want to test fully.
        With your replacements, perhaps you are fitting the wrong voltage LEDs ? Maybe detail your strip and the replacements so it can be figured out, it's hard to say without knowing the details.

        I use the LED tester for a quick test then use my bench power to test properly.

        Comment

        Related Topics

        Collapse

        • nubinator
          how can i test individual leds without tester
          by nubinator
          Hello I have TCL 65S4 and it has no backlight, seems common problem on this tv to have bad LED's. I have no tester though I thought I could just test each LED with 2xAA batteries for 3v but it doesnt light up at all?
          I saw a vid with LED tester on this TV and it had 130v for 1 good line which is 24 LEDs does that mean it needs around 5.5v per LED?
          10-25-2022, 11:05 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
        • Pipolups
          Corsair K70 LUX RGB dying LEDs
          by Pipolups
          Hi there !

          I'm having an issue for several weeks with my quite old K70 LUX RGB keyboard. I haven't used it for few months, and once I setup up again my desktop computer, I got several dead LEDs on that keyboard. I tried the Corsair troubleshooting thing (disabling options in iCUE, ...) but nothing changed so I conclude that for some reason some LEDs went in retirement...😅
          Decision taken to change these LEDs as I have access to desoldering iron and binocular magnifier, I wrote a ticket to tech support, hopping to obtain the LEDs reference and... They refused to tell me 🙄...
          10-08-2024, 11:58 AM
        • edugimeno
          Finding the wrong part at a loooong led strip, part works fine, part flickers, all parallel...
          by edugimeno
          Hi There!
          I'm trying to help my friend who owns a restaurant be just bought.
          He has a very long LED strip running along all the walls and columns. The strip is attached facing down 2in above the floor, using a wall panel that ends in a metal rail that finishes the panel underneath
          It's stuck using, I guess, the 2 sided tape that comes with the strip
          The issue is that like 1/2 of the full length, including 1/2 one wall, another entire wall, and one column, flickers after 4 or 5 minutes ON. Particularly it flashes staying OFF most of the time and flashing ON for 1 tenth...
          09-05-2024, 09:34 AM
        • jimbofz
          sharp LC40ELE 600E standby only faulty backlight
          by jimbofz
          Hi this sharp was stuck in sby 5v sby volts present.
          after the usual checks i jumped the psu with 470ohm to panel on and 5v sby to power on .
          all supplies came up 12v etc ,
          so after trying many times to get it to start in s/mode vol_ and source, then powering on no luck
          the sby led remains red and not even a flicker from remote control
          i decided to open up to inspect the leds
          i found two s/c and 3 would light fine
          but had lower resistance when checked
          as my meter on diode test mode would not provide enough voltage for them to light i...
          01-12-2022, 05:23 AM
        • Loading...
        • No more items.
        Working...