quiet.. like hard to hear?
quiet.. like 'this is my artistic expression to label the sound' ?
hard to hear could be a loose connection.
if the sound isnt coming out right, it is the same as not plugging the headphone jack in all the way.
if any pins are bent, it could do the same thing.
if any of the soldered pins have become undone, it could do the same.
if the headphone jack is perfectly okay.. then you need to make sure you have viewed all of the volume sliders.
when all of the volume sliders are at maximum .. it would appear you need somebody to tell you something with the soundcard is broken.