SuperDrive on iMac Keeps Ejecting Discs
I've been having trouble with my early 2009 iMac's SuperDrive. Recently I'd been having trouble reinstalling a 3rd party app after ML upgrade, and the install CD was getting stuck. I did have to pop it out manually using a card to gently make it come out. Now the drive will only eject every disc I try to insert. Is the drive toast, or is there a way to koax the drive to take discs again without having to open the iMac? It's obviouosly out of AppleCare, so if I have to replace the SD, what should I get, and how much can I expect it to be to get someone to install it? This has been one **** of a computer and I want to keep everything on it running right, even with its age. I just need it to last about 2 more years, then I will be looking to upgrade. Also as an aside, will the external SuperDrive work on this kind of iMac? I know it's meant for use with the MBA and other notebooks, but I am curious if that could be an option for me in this situation. Thanks!
iMac, OS X Mountain Lion, early 2009 model