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CCTV Power Adapter Repaired

By on June 13, 2017
how to repair cctv no power symptom











Visited one of my customer sites with the complaint of none of the CCTV Cameras were working.

Symptom found was-

On the monitoring screen it shows “No signal” error. By visual inspection I found power to the camera was not working. So I went to the DVR room and found that the SMPS provides the power to the Cameras has no indicator light glowing. I checked the SMPS output with multimeter it does not showed life.

Adapter is 12V – 2Amp. So customer have arranged new adapter and I have fixed the same and all the cameras were working now. Now I took the bad adapter with me to fulfill my curiosity that what went wrong with the adapter.

On return to the workshop I took the adapter on the work bench and opened it for inspection, visually I found everything was fine and there was no physical damage or burn marks only main primary capacitor was bulged.

 cctv power supply repair

Bulged Capacitor is of value 22uf 450V .So I have replaced the mains Capacitor. After replacement I have powered the adapter but LED Indicator not glowing. With the help of multimeter I started to test the voltages step by step.

First checked the DC voltages on the Mains capacitor I got 340V DC that means primary side up to mains Cap is ok. Still no voltages on secondary side. how to repair cctv no power

Checked secondary side components everything seems to be OK but no voltages so up to LNK666E IC there were no voltages. LNK666E is a 7 Pin IC (High-Power Off-Line Switcher with Accurate Primary-Side Regulation IC).

So this is the one component which I am unable to check, so on doubt I have arranged the new IC from our market.

how to fix cctv power supply

After replacing the IC I have powered the adapter and see.

repairing cctv


This way I have brought this adapter back to the life.

This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.

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Note: You can check his previous repair articles in the link below:




  1. Parasuraman

    June 13, 2017 at 6:55 pm

    Very good!

    • Yogesh Panchal

      June 14, 2017 at 7:12 pm

      Thank you sir,

    • parashu ram singh

      June 23, 2017 at 4:58 pm

      Yogesh Panchal ji,
      i am really very oblige to you for giving such wonderful information
      about faulty supply correcting method.
      right now, would you please forward motherboard of computer hardware
      different different if possible i am also interest and now about
      hardware as well as software engg. and i would like to much thank for
      hardware knowledge in computer era which is wast range today and
      thing about VVLSI and super computer circuit if possible. i am not
      in position to seen any supper computer still got master degree in
      software engg. and programming many popular languages like c, C++, java
      jsp asp, Sql, Visual, foxpro, and many other....
      i am again giving heartiest thanks for updating my knowledge and hope you pleas give me such type circuit ...
      parashu ram singh
      india, up, Lucknow

  2. Lad

    June 14, 2017 at 12:40 am

    Good work.
    I am still a newbie in power supply repairs. Do you think you could have used an oscilloscope to check the source pin of LNK666E to see if LNK666E works properly( to check if it sends pulses?
    Can anyone confirm?

    • Yogesh Panchal

      June 14, 2017 at 8:03 pm


      I don't Have oscilloscope; As you can see very few components on the PCB it hardly took 25 minutes to check all the components except LNK666E you can not check this IC for malfunction with the multi meter,Testing Voltages on this IC it gives 175V DC on Pin no.7 which works as "DRAIN" and is connected on primary side winding of the transformer and i am not getting any voltage on any other pins of this IC hence on assumption I replaced the IC & it works.

  3. Jai.

    June 14, 2017 at 1:55 am

    Nice job Yogesh

    • Yogesh Panchal

      June 14, 2017 at 8:04 pm

      Thanks! Jai

  4. Vikrant

    June 14, 2017 at 3:42 am

    well done sir !

    • Yogesh Panchal

      June 14, 2017 at 8:05 pm

      Thank you Vikrant.

  5. Anthony

    June 14, 2017 at 3:50 am

    Good repair work Yogesh !

    • Yogesh Panchal

      June 14, 2017 at 8:06 pm

      Anthony thanks for your comment.

  6. Henrique Jorge Guimarães Ulbrich

    June 14, 2017 at 5:39 am

    Good service, Mr. Yogesh Panchal.

    • Yogesh Panchal

      June 14, 2017 at 8:07 pm

      Thanks for your comment

  7. S Ramachandran

    June 14, 2017 at 11:20 am

    well done ...yogesh

    • Yogesh Panchal

      June 14, 2017 at 8:08 pm

      Thank you sir,

  8. Suranga Electronics

    June 14, 2017 at 2:31 pm

    Very good repair

    MR,Yogesh... Well done

    • Yogesh Panchal

      June 14, 2017 at 8:08 pm


  9. Albert

    June 14, 2017 at 9:36 pm

    Good clean and straightforward repair Yogesh!
    What would power adapters be without these (mostly bulged) e-caps?
    And thanks for the update on the LNK666E 7 Pin IC specs.

    • Yogesh Panchal

      June 15, 2017 at 4:53 pm


      Thanks for comment.

  10. Robert Calk

    June 15, 2017 at 2:28 am

    Good job, Yogesh.

    • Yogesh Panchal

      June 15, 2017 at 4:53 pm

      Thank you Sir.

  11. Humberto

    June 15, 2017 at 2:41 am

    Good repair Yogesh, I really appreciate your articles.

  12. Yogesh Panchal

    June 15, 2017 at 4:58 pm

    thank you.

  13. Justice cele

    June 15, 2017 at 7:40 pm

    excellent steady but sure skills thanks Yogesh.

  14. Yogesh Panchal

    June 15, 2017 at 9:23 pm

    thanks for your comment.

  15. Richard

    June 16, 2017 at 4:19 am

    Nice one

  16. Yogesh Panchal

    June 16, 2017 at 4:42 pm


  17. Christopher

    June 18, 2017 at 5:38 pm

    Hoops, this was awesome.

  18. Yogesh Panchal

    June 19, 2017 at 1:57 pm

    Thanks for the comment.

  19. Ulises Aguilar Pazzani

    July 11, 2017 at 12:25 pm

    nice fix , thks for sharing


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