or a music sample on the windows media player-
hmm
your repair guy could have checked it a little better with some music and such.

When I work on my parents computer - i double check everything - because they are nervous about exploring how it works.

If you still have problems and have to take it again ask him to test a bit more for you. and verify all sounds are working.

could something be loose inside from the drive - did it get bumped around?
Be cautious as bumps or drops might cause hard drive to malfunction
i don't remember if XP auto parks the hard drive. { a protection thing for hard drive bumps etc}