Ballast or bulbs?

Old 11-02-04, 07:22 AM
Visiting Guest
Posts: n/a
Ballast or bulbs?

I am having problems with fluorescent lights and would like to know how to tell if the problem is with the bulbs or the ballasts.

I have 7 "shop type" fluorescent lights in my basement (2, 48" bulbs each). The fixtures and the bulbs are the probably the most inexpensive type you can get. The fixtures are 6 years old, some bulbs are original, others replaced.
Every since they were new (house is 6 years old too), I have has problems getting them to come on after they have been turned off for a while. So I have just been leaving them on all the time. Usually if I flip the switch on and off several times they will start. This time I have 3 that are being stubborn and won't start. Some will flash a bit, but never start. I would like to turn these lights off when not needed.

So, is there any way to tell if it is the bulbs or the ballasts, short of trial and error? I would assume these fixtures aren't worth the cost and effort to replace ballasts, correct?

Old 11-02-04, 05:29 PM
Join Date: Sep 2002
Location: welland ontario
Posts: 7,932
Received 488 Upvotes on 402 Posts
The only way I can tell if it is tubes or ballast, Change the tubes. If they still don't come on, then it's the ballast.
Old 11-02-04, 05:42 PM
Join Date: Sep 2000
Location: United States
Posts: 17,733
Upvotes: 0
Received 1 Upvote on 1 Post
If the ends of the tubes are dark, it's probably the tubes. If the ballast is oozing, it's probably the ballast. If neither, then follow Joe's advice. As you say, you can probably buy a new fixture more cheaply than a ballast.
Old 11-03-04, 12:42 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 26,286
Received 1,840 Upvotes on 1,647 Posts
Some fluorescents simply don't like to start if it's cold and can be a real pain in the winter. Start with the bulbs since they are easier & cheaper to replace than the ballasts.
Old 11-03-04, 10:18 PM
Join Date: Oct 2004
Location: Yorba Linda, CA
Posts: 325
Upvotes: 0
Received 0 Upvotes on 0 Posts
Lamp manufacturers have started making several types of 4' fluorescent lamps that all look much the same, but require different ballasts to operate.

Look at the ballasts in your fixtures and see what sort of lamps they are supposed to be operating. You're looking for the wattage; it will be somewhere between 25 watt and 40 watt. Verify that the lamps you are using are the type specified on the ballast.

Check to see if the lamps you have are called "Homelights" or some such. If they are, try a better grade of lamp - a lot of ballasts won't work properly with Homelights (or Resilights) in them. If the fixtures still don't operate, the ballasts have failed.

A good 4' two lamp strip fixture is about $30. A ballast for one of these is about $13. If the sockets are good, I'd replace the ballasts. Get good ballasts - like Advance, Universal, Magnatek or Valmont.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: