I assume this kind of question is as applicable to non-car audio but
i'm sure repair costs are quite different.

Our car deck (default 2001 Toyota Corolla CD/Radio) has stopped
recognising CDs, or is at least very spotty about it. You put a disk
in, it scans it for longer than usual, then comes up with Err instead
of showing the track and time index that it would if it had started
playing. This happens with both original and burnt disks.

Sometimes ejecting and re-inserting will work. Sometimes when it is
currently working, skipping forward a couple tracks causes it to lose
tracking and fail. To me it seem to be on the verge of failing since
i can't reliably make it fail nor reliably fix it if it just doesn't
want to read cds that day.

I tried a cd lens cleaner and that didn't seem to help at all so i
assume it's a case of the lens being out of alignment or something
like that. Not hard to believe with all the vibration/bouncing that
goes on in a car.

Is this a common problem that anyone can remedy by taking the radio
apart and tightening a screw or something? Or is this something that
needs to be done by a 'professional' and therefore i'm better off just
buying a new deck?

p.s. I was all set to buy a new deck so i took this one out to check
the wiring and antenna plug. After re-inserting it doesn't fail as
often. But it still does sometimes. This is what got me thinking
that maybe it's repairable instead of a completel writeoff.

Any thoughts appreciated.