I might buy a stock CD player from a '91 T/A, but the owner says it's showing a code, the volume button is worn, and there's a crack in the lens. Is there a place that can fix these problems? Can any radio shop fix it?

 

Unless you're building a show car there really isn't a reason to use a beat-up stock cd player.

The code you're referring to is probably the "LOC" code check out this thread for it --> https://www.thirdgen.org/techbb2/sho...hreadid=263851

Some dealers will charge you $40-$100+ to fix that and it only takes a few minutes.

As for parts worn, I guess you could try getting another donor unit and making one good unit probably. My GF's Alero had a problem with it's stock CD player. Basically it was a sticky CD Tuner Button, sometimes it would work if it got really hot outside other times it wouldn't. We called around and the cheapest place we found was $45 bucks to look at it and they didn't even know if they could fix it. I went and bought a replacement cd player (stock) off eBay for ~$30.

I wouldn't even waste the time trying unless you can find a place to fix it cheap. If you plan on upgrading to different speakers just get the aftermarket hu and call it done.