optoma chainsaw

hey there, i was hoping someone out there could shed some light on a disturbing problem i am having recently. during a film the projector (an optoma 732h) started making a really awful noise that sounds like a blender or something. now it does this every time i try to turn it on and soon shuts itself off. i emailed the optoma tech people who supposedly get back to you in 24-48 hours, but haven't heard anything. the only idea i had which i read on their website was that it may been clogged with dust or something, so i vacuumed it like they suggested, but still the same problem. i would really appreciate any insight. thanks a lot!

andrew