What would cause bulbs not to work?

there is only four parts to a 9100 overhead projector. There is a micro switch by the fan, when pushed the fan should spin. Then there is a resistor (big white rectangle), a diode that reduces the voltage from 120 to 82 volts, and finally the lamp socket. If the fan spins, look at the lamp socket you may have to look into the mirror to get a good angle and make sure that there is not scorching or black marks, (some times the sockets fuse). If the fan spins and the socket looks good you will need to use a meter. But I would suspect the resistor first. Meter the left and right side to check for voltage.

mark
November 2010