T5 lighting dim on one side

[Instigate]

I got a used 36" T5 fixture and today when I went to turn the lights on I noticed it was very dim, then I noticed that all 4 bulbs are dim on one side. I'm assuming something is wrong with the fixture. Is this a common problem? Is it worth trying to fix?

 

[Sacohen]

I got a used 36" T5 fixture and today when I went to turn the lights on I noticed it was very dim, then I noticed that all 4 bulbs are dim on one side. I'm assuming something is wrong with the fixture. Is this a common problem? Is it worth trying to fix?

It's either the bulbs are old and need to be replaced or one of the ballast is bad and needs to be replaced.
It's not hard to replace a ballast.