At 09:28 PM 4/24/2011, Michael Rasmussen wrote:
>On the chance it's not the bulbs, it's the _____, what should I check out?

Rated life of bulbs
Rated voltage of bulbs (bulb life goes down with the fifteenth power
of voltage increase over rating while brightness goes up with the
fifth power - rule of thumb)*
*this is why if you buy the miracle last-forever light bulbs from the
catalogs you'll find they're rated for 130 volts.
Vibration, especially of a filament that's not adequately supported
for that service.
Insufficient ventilation.

As a sort of silly example...rated life of a 3600K photoflood bulb is
one hour.  Or was in '70 or so.

Yrs,
d