What version of Windows are you using and have a look in device manager to see if there are any error messages.

Is the drive seen in bios?

Windows XP OS.  Drive is not recognized in bios.  I get a "Fixed Optical Drive Not Found" message at startup. 

suggest you physically remove the drive then reinstall it in the first instance to rule out a purely connection issue.

Tried that a couple times.  Still won't recognize the drive.  Not sure what else to do.  anything else I might be able to try??

p.s thanks again for everyone/anyone's input!!

you may have to bite the bullet and get a new drive.

I am having a similar problem with a brand new Nec ND-6550A in my Inspioron 8200. Sometimes it takes a long time for the POST check and then says "fixed optical drive not found." If I immediately power down and power on again, invariably the next time it finds it. This does not always happen and it seems more likely to glitch if I have a disk in the drive. I changed the POST check from minimal to thorough in the BIOS and that seems to have reduced the frequency of this problem.

I have been too lazy to recheck the cables - although if I press on the drive faceplate it does not seem to make any difference.