Fluorescent light fixture: should it be able to hum if I've turned off the circuit (breaker)?

Question

I think I need to replace a ballast and wanted to check it out last night. But my wife and mother-in-law were in the kitchen so I kinda rushed things. I turned the light on (the lights don't come on but the fixture hums) thinking when I cut the right circuit the noise would stop. It never did. Is it more likely I missed the circuit, or could the humming have continued in spite of the fact I cut power to it?

Note: I did replace the bulbs, unfortunately the new ones don't work either.

Answer 1

Sounds like either something is miss-wired, you have bad bulbs, or your light fixture is bad.

Replace the bulbs. If it still hums, I'd start checking all the wiring to make sure it is correct. It shouldn't hum if there is no power going to it. I'd say you have power going to it when it hums.

Turn the main power off and see if it still hums. I wouldn't work on it if you hear it humming. You run the chance of getting electrocuted. I'd turn the main house power off. You may have power coming in from somewhere else or you may have picked the wrong circuit breaker. You might need to get an electric tester to figure out where your wires run to.

Answer 2

Its the ballast or somone has hooked the wires up wrong pos. to neg or neg to pos.