Disc on iMac does not eject using Terminal or any other method?

Hello, I am on a 2007 2.8 GHz intel Core 2 Duo iMac, and the DVD will not eject no matter what I try. I have tried all the following:

1) Restarting while holding down the mouse button

2) Restarting while holding down Option, then pressing Eject once Startup Disc appears

3) Opening Terminal, typing in drutil tray eject (and drutil eject)

I can hear the machine give a small whimper, as if it tries to eject, but it doesn't try for too long—just one second, one whimper, and then it stops. It isn't like those times when you hear the machine struggling for a while with the disc.

Also, once I try any of the eject methods (including the regular Eject button), the disc disappears from the desktop and appears to be unmounted.

Any suggestions?

Thanks!