How do you know if you have to change a ballast?

Question

I have 3 light fixtures, 2 of which looked like the bulbs were burnt out so when I put in new bulbs and they still didn't work, I learned that's because the ballast needs to be replaced. There is 1 more light fixture that is a two-lamp fixture, and one of the bulbs has burnt out and the other one is still working but the light is very dim. I'm wondering if that fixture needs to get the ballast replaced too because someone told me that if there is light, then the ballast does not need to be replaced.

Answer 1

In flourescent fixtures, usually when the ballast is going the lamps flicker - sometimes regularly, sometimes intermittently. Seems as if you just have bad tubes in the fixture. Won't hurt to replace them - and if their light is not up to par, or they flicker, then you know the ballast has to go, too.

Answer 2

I think you'll find that it's cheaper to replace the fixture than the ballast. Plus if it's an older unit it isn't that efficient. The older fixtures have a heavy magnetic style ballast which is inefficient and wastes energy by generating a lot of heat. The newer units with the smaller tubes have an electronic ballast which is very efficient and generates little or no heat.

Answer 3

Everyone Else has covered the ballast troubleshooting thing.
I just wanted to say that if you DO need to replace the ballast. You may want to think about changing the whole fixture as ballast by themselves are 90% of th price of a fixture (unless real decrotive).
to have them shipped is crazy as they weigh so much. most ballast that I have changed have been a real pain and usally invole taking down the fixture any way.
good luck

Answer 4

If your going to replace the ballast in one chances are they are all going, for manufacturers seased to manufacture fluerescent lights with ballasts years ago, because the ballasts leak and they give off a harmful gas, I would look for another fixture without a ballast that would fit there, it will cost you about the same as having the ballasts changed in your old lights and you will be more energy efficient.

Answer 5

You have just described the exact senario in which you will need to replace the ballast. Just make sure that you did replace all the bulbs, because the other could be out as well. Hope this helps.

Answer 6

The second one probably just needs the bad bulb replaced.
Usually if the ballst is bad you have noticed a smoky smell at one time or another.

Answer 7

Usually they stink, They leak a brown guey substance, get on a ladder or chair and try and smell right in the middle. They are fairly easy to change but sometimes cost more thant the fixture itself.

Answer 8

Try the two new bulbs in it and see what happens.

Answer 9

if the ballast feels cold it is bad

Answer 10

It is the earth leakage Dear PD between live and negative dropped