Soundproblem

Hi,

my son's GBA suddenly does not play the sound with the build in speaker as
loud as before. You can hear the sound only very extremely muted though the
sound level regulator is at maximum level.

This issue is independent of the game to play.

We do not have ear plugs to check whether this output is ok.

Do you have suggestions about this issue?

Thanks in advance!

Regards Guenther from Germany