Servicing 48 LED Random LED Light

By on May 30, 2018
led light repair

 

 

 

 

 

 

 

 

 

led random light repair

This random running light is one of the products that I deal with in my hobby sales. This was brought to me by a customer after almost an year stating that it was dead. I opened it and after cleaning of cobweb and dirt of dead insects inside, took it up for diagnosis.




On checking with my Analogue Multimeter, I could make out that one resistor was burnt  and three LEDs were short. Replaced these. While replacing the LED, we need to follow the R G B written on the board for selecting the correct colour of the LED. Did a thorough retouch of all solder points.  Switched on and it worked. As the IC number was not written on the top, I suspected it could be underneath and removed it. It was there on the bottom (one of the cheap Chinese tricks to avoid copying!) You will also notice that the colour code on the resistor is absurd! (I compared the value of the resistor with another new light from my stock and found it to be 33K!)

repair led light

how to fix led light

Looked for datasheet of this IC, but unavailable as expected!




Provided an IC socket and put the IC back.

led light fix and repair

Assembled the unit back to its original condition and switched on.

fixing led light

These are the components replaced:

how to repair led light

So, my satisfaction list lengthened further!

 

This article was prepared for you by Parasuraman Subramanian from India. He is 69 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.




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You may check on his previous repair article below:

http://jestineyong.com/crude-drawing-to-find-out-burnt-components-part-number/

 

Likes(59)Dislikes(0)

15 Comments

  1. Paul Preston

    May 30, 2018 at 11:16 pm

    You said you removed the IC but you didn't state the part number. Do you still have the IC part number available?

    Likes(1)Dislikes(0)
    • Parasuraman

      May 31, 2018 at 7:32 pm

      Kindly zoom and see the image of IC. It's readable.

      Likes(0)Dislikes(0)
  2. Robert Calk Jr.

    May 31, 2018 at 6:26 am

    Good job, Parasuraman.

    Likes(1)Dislikes(0)
    • Robert Calk Jr.

      May 31, 2018 at 6:30 am

      Oh yeah, I hope our friend Albert doesn't get mad at you for using your VOM. lol

      Likes(1)Dislikes(0)
  3. Albert

    May 31, 2018 at 7:29 am

    Indeed another pro job done Parasuraman. It seems likely that the device with the 5DF2433E still is somehow 'copyprotected' since no datasheet exists and the chip still can't be found anywhere either. Or it is not the correct chipmarking after all?

    Likes(2)Dislikes(0)
    • Parasuraman

      May 31, 2018 at 7:33 pm

      Possible!

      Likes(0)Dislikes(0)
  4. James

    May 31, 2018 at 2:16 pm

    I thought that was a smoke alarm' :[) lol

    Likes(1)Dislikes(0)
  5. Suranga Electronics

    May 31, 2018 at 7:38 pm

    Good Reair Job Mr,Parasuraman

    Likes(1)Dislikes(0)
  6. Michael Ripley

    May 31, 2018 at 7:48 pm

    The pcb was printed with "30K" under the resistor. Just an observation.

    Badly marked IC are very annoying. Very common in automotive ECU and increasingly seeing it on laptop motherboards.

    Likes(2)Dislikes(0)
    • Robert Calk Jr.

      June 1, 2018 at 9:29 am

      It's also annoying when the PCB and the schematic doesn't match.

      Likes(1)Dislikes(0)
    • Christian Robert Adzic

      July 6, 2018 at 9:17 pm

      In automotive ecu's a very common labeling is a so called "masking".
      Some of masked parts list can be checked here:
      http://www.autotronika.pl/files/file/MASK_SETS_by_Autotronika.pdf

      Also the same situation on PC mother board, laptops etc...

      Likes(0)Dislikes(0)
  7. Hakan

    June 1, 2018 at 4:25 pm

    Hi why did you use IC SOCKET.. Was the IC damaged..

    Likes(2)Dislikes(0)
    • Parasuraman

      June 1, 2018 at 10:33 pm

      Because, the PCB tracks were not good quality and I wanted to avoid a resolder in case the IC fails and I have to replace it from salvaged similar lights.

      Likes(1)Dislikes(0)
      • HAKAN

        June 2, 2018 at 7:40 pm

        Thanks

        Likes(1)Dislikes(0)
  8. Christian Robert Adzic

    July 6, 2018 at 9:19 pm

    Great Job!
    The ic could be a uC, maybe some sort of attiny 85 or so.
    Checking the circuit could be maybe identify if it is a attiny 85 or so.
    In many china tools could be found a uC that family.
    Probably also a clone/copy of the original...

    Likes(1)Dislikes(0)

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