Trouble with 4' 3-T8 fluorescent light fixture

[domenic__]

Dear Forum,

I need help with a kitchen fluorescent light (see

. After switching it on for 3-4 minutes, two of the tubes on the extremities go off while the middle tube remains on. Replaced tubes but to no avail. Would this be a ballast issue? Thanks.

[Meat Plow]

). After switching it on for 3-4 minutes, two of the tubes on the

Not much more inside but a ballast and wires.

[willshak]

on 10/12/2007 5:25 PM domenic_ [e-mail] said the following:

). After switching it on for 3-4 minutes, two of the tubes on the

Replaced all 3, or just the outside bulbs?

[domenic__]

I replaced only the 2 tubes but I did swap them around with no luck ....

[Joe]

If the problem didn't move with the lamp movement, then the wiring/ connections/ lampholders are the cause. Odds are the lamp sockets themselves are tired, corroded, poor contact. Replacements are readily available and easy to swap out. HTH

Joe

[Smarty]

Could also be the ballast. Some of the Home Depot T8 fixtures I've installed use an electronic ballast which independently drives the T8 tubes. I've had several fail in such a way that one or more tubes stop working while other bulbs in the same fixture continue to work fine. Some of the new "programmed rapid start" electronic ballasts use separate starting circuits which are independent.

I've also replaced a lot of cheap 2 lamp T8 electronic ballasts where one tube would still start but the other would not/ This is actually a common failure mode for the lowest cost Home Depot T8 fixtures I've installed.

As Joe also points out, the connections and lampholders are suspect, and Home Depot fixtures have really crummy lampholders on their lowest cost fixtures.

Smarty

[domenic__]

Thank you all for your valuable input.