DLP blue screen AV mute

Hi. I have this DLP: Mitsubishi XD80U and when it comes on, it shows in lower right corner "No signal" and then it goes to only blue screen and in the middle :"AV mute". When I press any button on remote or unit, picture from DVD player comes on shortly and goes back to AV mute with blue screen. I switched yellow video cable with S-video cable and same thing. Any idea? Thanks in advance:helpme

Try with another DVD player to make sure it's the projector and not the player. Borrow a player from a relative/friend if you have to.

I was running the projector at home on my DVD player a week ago and it was running fine. I brought it to my buddy to watch boxing and from the beginning it was doing the above described. We tried video game box/TV/DVD and it was doing on all signals so I brought it back home and tested on the DVD it used to run at home and it's the same problem. I didn't drop the thing so It's a mystery.

Is it still under warranty? If so, you may want to have it checked out.

No warranty in my case, I would already use it. I just fought some one might be experienced in this type of problem so well, I am on my own I guess.
Thanks anyway.