My kitchen has 9 26W fluorescent can lights (not CFLs - they have external ballasts). Often when I turn the switch on, particularly after they've been off for at least several minutes, about 4 of them won't light. They'll flash momentarily then stay dark. If I unseat the bulbs (handy being very tall :) ) and reseat them a time or three, the lights will come on. I've tried replacing bulbs, to no avail.
I'd assume bad ballasts, but a couple of things make that less likely in my mind:
- While it's usually about 4 lights that don't come on, it's not the same 4. Some more commonly have the problem, but all 9 have at some point.
- This has been happening since the ballasts were new (about 2 years ago). It might be getting a bit worse (i.e., more lights out on average) over time.
The lights are on a dedicated 15A circuit. They're switched by a 3-way switch. The ballasts are Sylvania QTR1x26T4. The wiring, circuit breaker, fixtures, ballasts, and bulbs are all about 2 years old.
Anybody know of possible causes for this behavior?