T-5 bulbs only flash once

[Frtdrmrose7]

I have a Marineland T-5 fixture I was given by a friend. The problem is when I plug the fixture in and turn it on I get one quick flash from the bulbs and that’s it. They only flash once, if I turn it back off then on no flash. I only get the one flash after powering the fixture. I don’t want to go out and spend $$ on new bulbs to find out it’s something else and this should go in the trash. Any advice is appreciated.

 

[Fudsey]

Might be the ballast going. Is there anyway to test the bulbs in a different fixture?

 

[Potatohead]

Ballast

 

[Daniel Waters]

Could be a bad ballast or one of the bulbs is bad. I've had instances where 1 of the 2 bulbs is bad and I would get a flash on and off like you are describing, so it doesn't have to be the ballast. Unfortunately, you will need to test your bulbs on a known working fixture or borrow a couple of known good bulbs to try out.

 

[Frtdrmrose7]

I’m going to see if anyone I know still has a T-5 setup so I can test these bulbs and ballast.

 

[Big E]

You probably have a bad bulb that isn't completing the connection. The bulbs that flash are good, so you have to test/replace the bulbs that never go on till you figure out which one is bad.

It may also the that the bulbs that don't flash just don't have a good connection, so that's the first thing you want to make sure of. Re-set them in the sockets is all that needs to be done and also inspect the prongs.