RBM wrote:
What you have is essentially two fixtures built into one housing. Each
operates independently, they're called "Circleline". The only
connections you have, other than power are the four prong jacks that
plug into the bulbs,so there is not much you can check.Your
description does indicate an overheating ballast, as Jeff described.
All fluorescent ballasts since the 70's are "T" rated and will turn
off when they overheat, then turn back on after they cool. My
suggestion would be to scrap the fixture and replace it with a
straight tube fixture that uses electronic ballasts, which are much
more reliable

I agree with that suggestion and I might add that lamps will be less
expensive and easier to find as well as offer more choices.


--
Joseph Meehan

Dia duit