Don't Miss

Electronic Ballast Repair

By on June 13, 2017
fluroscent lamp ballast repair










I have a fluorescent light fitting in my kitchen which has 2 fluorescent tubes. Some time ago one tube failed (or so I thought) and I didn’t bother to change it as the kitchen was still brightly lit with just one tube. When the second tube stopped working I was forced to do something about it!. I changed both tubes with no success!

I eventually removed the light fitting and opened it up. Inside were two electronic ballasts. I immediately saw something was wrong when I noticed the plastic cover on one of them damaged through heat – see the pic below:
electronic ballast repairing
fix electronic ballast repair
electronic ballast fix
Upon removing the cover from the ballast I noticed that there was much to it. I measured the 2 switching transistors (MJE13007) and found them to be faulty. These were replaced with 2SC2335 transistors which I had in my components bin. I connected up one tube and the ballast and it worked fine.
fluroscent lamp ballast fix
I then removed the transistors from the second ballast and measured them. They measured fine, but the ballast would still not work. I eventually replaced the 2 switching transistors in this ballast as well and it worked. So the next time you have a problem with an electronic ballast from a fluorescent fitting open it and check before buying a new one. They can be expensive and more often than not they can be repaired.
This article was prepared for you by Mohamed Kikia from Durban, South Africa. He is employed full time as an Electrical Technician. He repair switched mode power supplies, coin comparators, arcade game monitors, LCD monitors and other electronic devices which people bring to him in his spare time an over weekends.

Please give a support by clicking  on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

P.S-If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!




  1. Raymond

    June 13, 2017 at 6:15 pm

    Great articles, love your work Jestine. Many thanks!

    • Jestine Yong

      June 14, 2017 at 11:41 am

      Hi Raymond,

      You are welcome but I have to thanks those who had contributed the repair articles.


  2. Parasuraman

    June 13, 2017 at 6:57 pm

    A good feed back on ballast repair.

  3. moshe jacobson

    June 13, 2017 at 8:44 pm

    thanks for the article.
    Amazing what can be repaired with a little effort.

    But what was the cause of the excess heat generated?

  4. Henrique Jorge Guimarães Ulbrich

    June 14, 2017 at 5:45 am

    But, if the 2 transistors in the second ballast have been measured and showed to be fine, why were them not working?

    • Justice cele

      June 27, 2017 at 3:30 pm

      Remember meter testing could give correct reading and yet the component fails to work, remember its a semiconductor. its best to put in circuit and see the behavior.

  5. Suranga Electronics

    June 14, 2017 at 3:07 pm

    Nice job

    Do continue..

  6. Yogesh Panchal

    June 14, 2017 at 7:10 pm

    Good Job!

  7. Albert

    June 14, 2017 at 9:39 pm

    I've seen a lot of these electronic ballast boards from the inside that were used on a turkey farmhouse. But instead of semiconductors, the only component that was defect almost every time was a 10uF 450V e-cap. And in almost all case the e-cap plus side leg connection was chemical damaged and broken of.
    After I read that the life in hours of these e-caps is very limited (200 hours
    or less?) I advised the owner to go over to start using LED lights instead.
    Thanks for the article with different ballast boards. My repaired ballast boards only used smd parts for all the semiconductors on it.

    • Robert Calk

      June 15, 2017 at 2:47 am

      If I remember correctly, the one I repaired had a bad diac and two bad poly caps. It also had a loose ground and some suspect solder joints.

  8. Robert Calk

    June 15, 2017 at 2:34 am

    Good job, Mohamed.

  9. Humberto

    June 15, 2017 at 2:43 am

    Great article with good quality pics. As you said, electronic-ballasts can be rapaired most of the times.

  10. Mark Tembo

    June 22, 2017 at 9:58 pm

    I have a similar problem, and I think after reading this, I should be able to repair my fluorescent tube as well.
    Thanks a lot!

  11. gabriel jerez

    June 24, 2017 at 7:56 am

    Good evening, please, can you send me the electric diagram of the saving bulbs and the ballasts. Thank you.

  12. Justice cele

    June 27, 2017 at 3:34 pm

    Good work keep doing it.

  13. Bufford Moore MD

    February 6, 2019 at 9:05 pm

    I live in the US and had a failure of a florescent light. I remembered seeing this article and was interested in seeing if it had the same fault. Upon opening it, I found the components to be potted in some sort of resin that I was not able to remove without damaging the components. As all the fixtures in that room were of about the same age and several lights were flickering, I opted to replace them all. There were, to my surprise, more than one brand of ballast. They were, however, all similarly potted when opened. Is that common, or just something required here?

  14. Md. Shahadat

    November 23, 2019 at 2:52 pm

    Dear Sir, this is Shahadat from Bangladesh.
    first of all thanks to you. its really great job.
    i am verey much interested to learn to repair HMI. please send some article or book to learn repairing HMI


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.