Mac Mini wont start, but has repeating sound

I was using the Mac Mini (Mid 2007) just fine and it sundenly turned off by it self. When I tried turning it back on, the light turned on but it got this short squeaking repeating sound and just stays there with the sound. I tried inserting a cd, and it sops the sound while I´m pushing the cd in but it wont accept it, send it out and start the sound again. Any ideas?

How can I confirm if its a board, drive, etc. issue?

Thanks