Just a shot in the dark here.

Have you reset the lamp timer?

I was trying to figure out how to do that. I didn't see an option, but I don't have the manual. Is it in the normal menu or is it in the service menu?

I'm not a tech just used to work in a tv store.

Here is a link to download the manual. See page 95.

Here is a link that might be useful: Mitsubishi Owner's Manuals