First off i detest working on there projectors as they seem cheaply made. This one was just out for a clean & new lamp, picture was hardly visible in a pitch black room. As I was stripping it down I snapped the plastic cog that drives the lid so my fault my replacement. First tried fix cog with superglue and tape as seen on the mirror lid in the picture which worked for short period then failed again. Ordered replacement from ebay for £25 replaced and now working perfectly. Polarizers seemed scorched so had to scrub with abrasive cloth and liquid soap which eventually came clear. Half a bucket of dust was blown out and the optical engine was cleaned with ethanol. Picture now is a world apart from original as seen. This took 2 weeks and 5 strip downs to get it right which in the real world is not worth it( as cheap to buy new projector) unless staff members are willing to do it themselves, there are plenty of instructional videos on youtube. As I get a lot of work from this school I don't mind charging for a clean & new lamp but overall these particular projectors just aren't worth the hassle.