I have two overhead fluorescent light fixtures that are not working properly. After the switch has been turned on, the light bulbs might take several minutes before they actually come on. Sometimes, they will come on immediately. What can I do to fix it?
First, make sure that you are using the correct fluorescent bulb type for your fixtures. If it’s an older fixture, it likely uses a T12 bulb. Newer, more energy efficient fixtures, use T8 bulbs.
Next, check that the pins on each end of the bulbs are making contact with the socket. Not the problem? It could be time to replace your bulbs. A good indicator that it’s time to change the bulbs is if they get dark gray on the ends. Next time you change the bulbs, change them all at the same time. If you can’t or don’t want to climb on a ladder to change light bulbs, consider hiring a reputable handyman.
If changing the light bulbs still does not solve the problem, the problem is most likely with the ballast, a transformer in the light fixture that changes the voltage from 120 volts to the required voltage for fluorescent bulbs. If the ballast is wearing out, it could cause all of the symptoms you listed.
If the ballast is the problem, it’s probably time to purchase new light fixtures, which an electrician should install. Replacing just the ballasts in the existing fixtures could cost almost as much as a new fixture and take more time to install, plus keep in mind that if it uses the 40-watt T12 bulbs, those are being phased out in favor of 32-watt T8s.