Cannot get sound on stereo.

Just bought this - 3rd owner. Bought from a friend who had to buy the reset code
because other owner never recorded it. Everything has been reset according to the
instructions given and the car was driven 200 miles as instructed by the dealer he
spoke with.  

The radio shows that is is on but there is NO sound whatsoever. Same thing with CDs.
Not even static - just silence. Speakers appear to be okay.  The phone no longer works
and the phone that is with the car actually may not be the right one anyway as it does
not fit the holder. There is a note in the manual that states if one component does not
work, the others might not. We do not need the included phone and would like to
remove.  My questions are - how can we get the stereo working?  Since the car is long
out of any warranty, can anyone safely remove the phone and will anything special be
required so that the stereo will work after that?  It also has a cassette deck but we
cannot try as we no longer have cassettes.

Help PLease - I need Music!