How do you know if an electrical balast is bad?

I am trying to change change some lights out but they wont come on. The breakers are on, the switch is on and no light is on. So i figure the ballasts are broken or damaged. How can I tell? How do I go about changing them? Getting them fixed?How do you know if an electrical balast is bad?Assuming that you are trying to replace flourencent lights do they have a starter 9older models do) Ceck to see if you have power coming into the light fixture(from the switch) you can use any cheap detecter just to see if there is electricity. If electricity is present then you can check on the outbound side (to the light) if there is electricity. if not then you have a bad ballast.

To change you need to undo the connection from the switch(turn off switch first) then splice in the wires to the tomestones(where the tube bulb fits) If the light is original there should not be a splice if the ballast has been replaced before then there will be a splice already. The color code should match up it is probably only red blue and green maybe a grew or white. When buying a new ballast make sure that the ballast and bulbs are compatible with each other. some bulbs require a higher start up so the ballast needs to be the correct type.

Check to make sure that the new bulbs you put in are for the starter that you have. That may be the answer now.How do you know if an electrical balast is bad?if you have power leaving the light switch and getting to the fixture and have new bulb(s) in the fixture then chances are the ballast is bad. If you have a volt meter or multimeter check the voltage at the light socket. Put one test lead on the socket base and the other in the center of the socket. If no voltage is present and you have checked the voltage coming into the fixture and its present there then you have a bad ballast. For High pressure Sodium and metal halide lights changing the ballast is a matter of shutting off the breaker taking the fixture down then take the light covers off and replace ballast.

For flourscent lights I check feed coming into light (ballast) if I have it there, I then check the voltage leaving the ballast. If no voltage is present then my ballast is bad. Shut off the breaker, remove bulbs and cover to flourscent light. Then change ballast.How do you know if an electrical balast is bad?If you have one light that is working properly, then switch out the bulbs, if a bulb works on one light-it should in another.