T5 New wave problem

[calvin_orchidL]

Hey all,

My T5 4ft 4tube fixture spontaneously stopped working yesterday. I've checked the bulbs and they're good. I'm suspecting that the ballast has blown; is that typical, considering I've only had these lights for 2 years (12-16 hour cycles, season-variable).

Questions
1. Does anyone know if this unit uses 2 2x54W ballasts, or a single 4 x 54W ballast? I can't find my allen key and it's a snow storm outside, so I can't bust open the thing to look inside. I'm hoping I might be able to rule out the ballast (ie if there are 2 2x54W ballasts, then it doesn't make sense both should screw up at once).

2. One of the sockets is a little broken (i.e. the plastic is a bit chipped) - doesn't seem logical that this should be a problem, but could one broken socket affect the whole lamp?

3. I have these lights currently mounted vertically (will change within 2 weeks...temporary experimental setup). Could this have screwed things up (doubt it)? The only thing that makes me suspicious is that another bank of T8s failed 2 weeks ago.

4. Any other ideas of what could be wrong? I haven't dropped the lights, nor have I exposed them to excessive humidity.

Thanks all