I have a fairly similar Beseler Dichro 35 that I use for 35mm. The lamp has lasted for years. A few things to check: Are you using the correct lamp? - there are a lot of similar lamps, and not all of them are designed for line voltage; are you operating the enlarger at the designed line voltage? did the lamp have fingerprints or grease on it? - these can make the lamp fail; was the lamp installed correctly? - this can be tricky, and what looks right may not be correct.