On Mon, 30 Apr 2012 14:58:27 -0700, Mike Easter
wrote:

I have 3 identical fluorescent fixtures in the garage about 15 years
old, 2 bulb 4' rapid start. A clue to their usage is that none of them
had had any bulbs changed in their life.

One of the units showed intermittent flickering sometimes one bulb was
good/bright, sometimes dim, the worse/dimmest bulb had a dark spot at
the end.

So I changed the bulbs, with no improvement. Used another new bulb.
Same thing. Took two working bulbs from the other fixture and put them
in. No improvement. I began to suspect something was wrong with the
ballast, but I wasn't smart enough to do any troubleshooting. All I
have is a little volt/ohm meter I use to troubleshoot computer power
supply problems.

So, I went to Home Depot and bought a ballast aided by an experienced
sales person who understood what fixture and bulbs I had. The new
ballast was not as 'fat' as the other but was the same length and color
coding of the wires.

I disassembled the fixture/ballast and replaced the ballast using wire
nuts acquired during the ballast trip and reconnected, reassembled, and
resecured the ceiling fixture.

No improvement.

Now I don't know if my original ballast was good or bad and/or if the
replacement ballast is good or bad. I would like to do some of the
diagnostic testing I didn't do during my original guesstimation that it
was/ must be/ the ballast.

How can I:

- benchtest my old ballast I removed
- test the integrity of the new ballast installed
- troubleshoot my malfunctioning fluorescent

If I could satisfactorily prove to myself that the new ballast isn't
good, then I could return it; but under the present conditions I have no
clue what is wrong.

There's only one thing left. One of the sockets that the bulb is not
making a good contact with the pins on the bulbs. (unless you got the
wrong ballast or wired it wrong).

An electronic ballast would have been the better replacement. They save
energy by using the newer low power bulbs and are less troublesome.

One other thing, did you check to be sure the voltage is correct to that
fixture?

If you insist on keeping the older fixture for appearance, buy a new
fixtire and transfer the guts from the new one into the old one. All
there is are ballast, 4 sockets, and the bulbs. You might have to drill
new holes to make the ballast fit, and some sockets may mount
differently.

Check the sockets first, both the fit against the bulb pins and the wire
connections inside.