Advice please about a CD problem

Two reasons a CD that used to work now doesn't are normally a scratch (most common reason) which if on bottom can be fixed with special polishes. The other reason is scratch on the top (taking off the aluminium that has the data) which is nigh impossible to fix, or CD rot, which is similar. That happens when there isn't ideal laquer on top and and the aluminium literally corodes.

Hold it up to the light. Do you see either scratches through the top or wierd crack like patterns?

The idea CDs are indestructable was a total myth, I ruined a few of them by letting the top get scratched, they jump like bad vinyl :(

(If it's a CDr all bets are off, they go with time anyway).

Thanks for that JC. There aren't any scratches and as far as I can ascertain there is nothing wrong with the top either. I find it strange that both CDs won't play!

Can you play them on a computer? Computers generally have much higher quality lasers in them so you could always copy it to a re-writeable disk. Otherwise try giving it a good clean, you can even polish them with toothpaste to get out fine scratches if you don't have anything else.

It does seem very odd. There is a little bit at the start (near centre) that has the info about what is on it then the actual tracks are laid out after that in a spiral. (Interesting little fact, the data per unit distance is the same so a music CD spins faster the closer it goes to the centre). So to not work at ALL implies damage to that sector in some way? The normal way they mess up if that isn't damaged is as I say jumping and maybe crackling.

Sure they aren't CDrs? Are they wierd in some way? Do they look clear/silver when viewed from below or the other colours CDRs have?

CDrs/DVDrs can just die over time, I have some that don't work now.

Definitely CDs, JC. And they worked fine before. I probably haven't played them for a few years. I find it strange that both don't work.