Lighting Issues - Help Required

Hi All,

Been out of fish keeping for a while and hoping that someone has come across this exact problem.

Problem:
I have a light fixture that uses an Osram dual ballast (2 x 58w T8's) running for +- 5 years. Over the weekend, after switching the unit on, both bulbs lit up but after a minute or so, promptly switched off. I opened the cover, unscrewed the bulbs and as I put them back in, the unit switched on again, this time staying lit for around 5 minutes before switching off again.

The problem has been narrowed down to either the bulbs or the ballast (I tested power coming into the ballast, but silly me did not test power out when bulbs turned off) but I need a proper diagnosis before purchasing something that is not required.

That being said, has anyone experienced this with their tank lighting? If so, what was the problem?

K