Headphone socket not working

Ive just brought a MixVibes U-Mix controler and the headphone socket doesnt work.
\ive tried a number of pairs of headphones.
All the volumes and levels are correct.
I took it back to the shop he plugged it in and it worked fine.
I got it home and it's not working again, i just get the same buzzing sound.
Could this be an incompatibility software issue.
\ive tried a number of pairs of headphones.
All the volumes and levels are correct.
I took it back to the shop he plugged it in and it worked fine.
I got it home and it's not working again, i just get the same buzzing sound.
Could this be an incompatibility software issue.