HELP! my DVD rom is locked

I was working on some HW with my Knoppix live CD last night. I got all my work done and saved them on a USB flashdrive.

As i restart my PC, the CD was spitted out, but the screen hanged in black. So i pressed the reset buttom and went back to window then went to bed.

This morning, i sticked my flashdrive in trying to print out the outputs and sources and i realized some of the files is corrupted and cant be opened.

I tried to put the Knoppix CD back in so i can rework the corrupted the part but that's where the problem comes in; the my DVD rom wont respond. I've tried the reject buttom on the actual drive and the reject buttom in Window. i've tried remove it in device manager and reinstalling it, but it just wont work.
Im using a SATA Pioneer DVR-212D DVD burner

has anyone encountered this problem b4? thanks

Unpug the computer's power cable for 5 minutes and see if the situation improves.