This article has been updated with new information and new products. It was originally published in 2017.
If you still have T12s in your building and they run on magnetic ballasts, you may soon face a problem: what do you do when your ballasts die?
Well, like T12s themselves, magnetic ballasts are becoming harder and harder to find these days. They're really no longer in production in the U.S., so most people today are running T12 fluorescents on electronic ballasts. What is a ballast? Read more.
Before we get into troubleshooting options, let's briefly determine how to tell if a ballast is bad.