Audio Systems: 96 Olds Aurora, olds aurora, repair expert

Question
I just bought this car used from my uncles car lot.  After a few days I found a cd i wanted... put it in worked fine, but then i noticed that my car's antenna was slightly damaged and would fall over if fully extended... so I unplugged the power to the antenna motor.  After doing this the cd player comes up with... E 21 when putting in a cd.  I tried replugging in the antenna to no avail.  My radio still works ok, but i'd love to be able to play cd's

Answer
I am not a repair expert, but I believe the E-21 is a laser read error :(
You need a new antenna and it does not have to be a powered one. Since the deck is ten years old and giving you read errors, it is time for a new one as well.
Spend as little as possible on the headunit.. you can find a good one for under 100.00.