I've just been handed down a 67 year old projector that has been through 2 other generations of my family. This gem probably hasn't been run in 30-40 years. I know very little about projectors, except have figured out how to get this one loaded and running. It is a 16mm Ampro Imperial Precision. It uses a Sylvania DDB 750w lamp. Everything is in working order, except when the projector runs for more than 10 seconds smoke comes from the vent above the lamp. I've had the whole lamp assembly apart and cleaned thoroughly but can't figure out how to stop the smoking. The fan runs well and blows a constant strong breeze through the lamp housing. Wires to the lamp socket look fine and not melted at all. Smoking stops almost immediately after turning off the lamp. Anyone out there know anything about these old movie projectors? Thanks in advance if anyone can help!