JBJ Light not working

[JoAnn VanDersarl <jmarella at attbi_com>]

As if this week hasn't been frustrating enough....

I just noticed that one bank of lights on my JBJ 4X55 fixture isn't 
working. It's not the bulbs, so I'm guessing maybe a ballast? Does 
anyone know if JBJ puts each bank on a seperate ballast? One row of 
lights is not working, while the other is fine. I thought I smelled 
something burning this morning, but didn't think to check the 
fixture. The other day the same bank went out for awhile but came 
back on, so I didn't think much of it.

Is it possible to replace a ballast and if so, how?

Thanks in advance.

JoAnn - who isn't real sharp when it comes to electrical stuff :)