Me too! See my (just revived today) thread. I know for sure it's the fan because a) taking it apart revealed a slightly cooked fan sitting in a puddle of black goo and b) when I strapped another fan to the exahust port, the projector works fine, albeit noisier.
I have narrowed down the right part number for the fan to three choices. I was hoping an AVS reader could help me pick one, else I'll just order both of the HD100 "fan motor"s and see which is the right one.