Light fixture emits a high pitch sound with no bulb

Question

I have a light fixture that hangs from the ceiling which no longer works with new bulbs. It uses Dulux D/E 18 watt compact fluorescent bulbs. I'm ok with it not working but when I turn on the light switch, it emits this high-pitch sound – even with no bulb. A simple solution to the sound is to just not use the switch but I need to use it power on other things. Can someone tell me what the issue is and how I can resolve it?

Here are some images of the light fixture itself and inside of it:

light fixture http://www.gobozzy.com/wp-includes/images/light/IMG_4622.JPG. inside fixture http://www.gobozzy.com/wp-includes/images/light/IMG_4623.JPG.

Any information would be greatly appreciated.

Answer 1

The noise is coming from the ballast (the part which converts 120 or 240 (or whatever the local standard is) VAC to the voltage and current required for the fluorescent bulb. Given that the fixture no longer works with a new bulb, that has failed, but some portion of it is still trying to work and the high-speed electrical switching common in newer-style ballasts is making the noise.

Best bet would be to replace that ballast (they do not live forever) so the light is useful again. Or, as suggested by @John, you could remove the power to the ballast (and remove the entire fixture, if you don't plan to fix it - a cover plate would go on the ceiling electrical junction box.) A third option would be to have the light retrofitted to an LED type fixture (which uses a different "ballast" or power supply) or replace the entire fixture.

Answer 2

The simplest solution would be to disconnect the electrical connection within in the light fitting. If the fitting in question is not the last fitting in the "chain", you might need to keep the incoming and outgoing switched connections joined to pass the power on to the next fitting.

Usual disclaimer - only do this if you know what you're doing and switch the power off first... If you're unsure, get an electrician in to do it.