Things to try to make the installation disk appear?

Question

My machine suddenly stopped burning CD's in all programs--iTunes, Roxio Toast, some downloaded freeware--and now blank or recorded CD's aren't showing upon insertion. I'd like to do a reinstall of Tiger but--duh--of course the disk isn't appearing on my desktop or anywhere else that I can see. I've rebooted and checked preferences under my menu and in System Preferences to make sure the machine is set so the Finder will open upon insertion of a disk.
I'm wondering if there are some key maneuvers I might try (5-6 years ago I recall someone holding some keys down and starting the machine at the same time, which produced a disk image) or if there are some programs--Toast, Flip Mac, etc.--I might be advised to trash. Or if there's a place to look for conflicting priorities that might possibly cause a freeze-up.
Any tips, advice appreciated.
Cap

Answer 1

Really? Not simply rubbing alcohol? Also, isn't this a matter of disassembling the machine? I assumed it would be strictly a professionalist/specialist's job.
I know I'll be glad when I can do an install, because I'm noticing all sorts of stuff on my desktop--two iDisks, .DS-Store pages, a network icon in a square, etc.--that didn't used to be there and won't go away. And in my finder window strange folders like .java, .MCLXC, .mplayer, .Trash, .Xauthority. that, whatever they mean (including the "."), appear to be useless, empty icons and permanent clutter. The Apple discussions website doesn't even want to accept my OS. I keep inserting 10.4.9, but it keeps reverting to 10.4.2. I'm beginning to think I may need to take this machine to the Mayo Clinic.
Cap
iMac 17 1GHz 768 ram   Mac OS X (10.4.9)