I recently purchased another pile of used projectors to repair and then send to Africa. However three of them need more than just cleaning. I have determined that the problem is in the optics. Basically the blue LCD is about 30-50% shot. There are lots of dark spots in a blue background.
I like the Epson LCD projectors because they are a lot more rugged that the Dell 2300MP DLP projectors. However the LCD's have an air filter and if it gets clogged the projector overheats and damages the LCD's. I explained how to replace the filter in a previous post.
Here is what the outside of them looks like.