Fluorescent light fixture, 2 bulbs. only one is lit but if I remove the lit one the other one lights up. I put the other bulb back in and it won't light until I remove the lit one, so no matter what side it is only one bulb will light up at a time.

  • 2
    Is the fixture new? Is this a new problem? It sounds like the ballast is weak. If new fixture returned it. If older and new problem, can probably replace the ballast.
    – crip659
    Sep 2, 2022 at 14:36
  • Edit to include brands, model numbers, etc. The more detail you can give us, the more likely we are to be able to answer your question.
    – FreeMan
    Sep 2, 2022 at 16:03
  • 1
    Has someone changed the ballast? Pop the ballast cover off and make sure the bulb types on the ballast match the bulb types you're putting in. Particularly "T8" (1" diameter tubes, diameter of a US quarter) vs "T12" (1-1/2" diameter). May be indicated as F40T12 vs F32T8 (see the T8/T12 in those numbers?) If feasible snap a pic of the ballast. Is the ballast melting goo out of it? Sep 2, 2022 at 17:20

1 Answer 1


Usually if a fluorescent fixture starts acting possessed, the ballast needs to be replaced. So I second the comments, especially the ones about posting some pix.

To fix, you could replace the ballast, but eventually the new one would wear out and you would have to do it again and again over the decades. Or, you could search for LED replacement bulbs that fit the fixture. They differ in terms of whether they need a ballast or not, so you might have to bypass the ballast to get them to work (depending on bulb). But you wouldn't have to worry about it any more, and LEDs can be even more efficient.

Here is an example of these LED replacement bulbs, but you have to find the right ones for your particular fixture:


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.