I've got a 10 year old Mitsubishi HC1500 that developed a loud whine at start up which would quiet down after a few minutes.... I tore it down and found the color wheel had been rubbing on the exit window mounting screw on the mounting bracket - see attached png. The aperture and and bracket show signs of serious overheating! It looks like the lamp was focussed on the aperture plate (top middle and caused overheating and deformation of the color wheel bracket?! I had replaced this lamp in August of 2012 with what I thought was a OEM lamp... I would attach a pic of the box label (which I keep the old original lamp in) but I'm apparently over the quota; maybe I can add in a follow up post.