Bad/old lamp. Resistance at a
plug, high resistance connection somewhere between
fixture and
dimmer, bad
dimmer,
dimmer set with a lower
trim,
dimmer soft patched at a lower setting, smaller wattage lamp in the
fixture,
DMX issue,
fader issue, light board issue, bad lamp
base, bad wiring to the lamp
base, bad cable or any connection there of, too low a
wire gauge feeding it. How's that for a starting
punch list. Is the light
bulb screwed in all the way?
You say the
fixture is not the problem. I assume that you started by swapping fixtures and the one that replaced it had the same problem. Next most easy is to swap the patch between a dim and bright
scoop assuming they are on differing dimmers. This will tell you if by plugging the
fixture into a known good
dimmer if the problem is before or after the
dimmer. If before the
dimmer or at the
dimmer, that's different. If after the
dimmer, it's a cable or connection problem.
The only thing you can do without supervision at this
point is to replace cables feeding the light. Given it's after the
dimmer, it should solve the problem and you know you probably have a cable with a loose connection, broken wires, or one of too small a
wire gauge for the distance traveled. If it did not fix the problem, you know it's actually the
fixture which you will have already crossed out by swapping fixtures, or between the extension
cord and
dimmer. That's easy to fix frequently but not something you school should be letting you fix without direct and compitent supervision. Same with doing the
dimmer to light board problems. Break something without being supervised or get hurt and it's more trouble than it's worth in doing it on your own.