One of two fluorescent bulbs flicker in single fixture. New bulbs and new ballast...what gives?

Question

I have a single fixture in my kitchen with two 4' fluorescent bulbs. There is no starter in the unit, just 2 bulbs and one ballast. Original fluorescent bulbs started to flicker so I bought and installed two new ones. The flickering problem remained. I then bought and installed a new ballast. Here is my problem...When I first turn the fixture on in the morning one bulb is dead and one bulb flickers and is partially lit. If I hit the switch two or more times both bulbs eventually light up. The wierd thing is that if I leave the fixture on for a while, then turn it off and on, both bulbs light simultaneously. The fixture only acts up after it has not been on for a few hours. I have changed the bulbs and the ballast, what else could the problem be?

Answer 1

You have a bad connection, take them out and check the sockets for burns or a partially missing piece.If its all right reinstall the tubes it only takes a 1/4 turn. Next twist the tubes slightly back and forth. It happens, sometimes its hard to make the connection in old fixtures.

Answer 2

I would check the wiring on the tombstone (where the pins on the bulbs plug in to the fixture). If they are loose you could get some flickering from a cold start. Twist them bulbs in there better.

Make sure you used the ballast that was recommended for the bulbs. There are T12 and T8 bulbs being used commonly in homes today. I would also check the wiring at the switch. Make sure those connections are tight.

Double check your wiring on the ballest as well. People get things mixed up all of the time and weird things can happen.

Answer 3

Fluorescent bulbs flicker. Even "non-flicker" bulbs flicker a little. The problem is that your household electricity turns on and off one hundred and twenty times per second (twice per cycle, sixty cycles per second in the US). This isn't noticeable with an incandescent bulb because the filament is glowing white hot and it takes more than 1/120th of a second for it to cool down noticeably. But a fluorescent bulb, being so much more efficient and cooler than its counterpart, dims significantly as the current alternates.

Answer 4

Just to re-enforce the most likely culprit already mentioned. Bulb could be loose at the sockets. Try and see if you can "bend" them closer to the inside of the fixture.

Answer 5

It could possibly have a bad connection where the ends of the bulb plug in. Try pressing the ends inward for a tighter connection. Hope this works for you.

Answer 6

There is one more possibility. If the ground wire isn't connected that can cause flickering. Check it.

Answer 7

My guess is the contacts--either loose or misaligned. They make better contact after they've heated and expanded. Don't know what you can do about it though, except replace the whole unit.

Answer 8

the problem is loose fitting bulbs

Answer 9

hard subject. check out using yahoo and bing. that might help!