A friend of mine bought a used car; it came with a in-dash Sony
CDX-4170R CD/RDS player, but no user's manual (for the Sony, not the
car...)

The CD/RDS player works apparently ok, but he's tired of the beeps
every time he touches a button. Can it be shut off in any way? He has
already tried several buttons but haven't found anything that offers
to turn off the beeps...

Cheers,
Christopher