Default [Q] volume doesnt work on HTC merg

My brothers phone is having volume issues. There is zero volume and if he tries to turn it up he gets a pop up message that says "adjust volume from accessory". Ive googled it but found very little, ive never even heard of it before. Also, if I go to volume settings I see the volume tab is grayed out...not allowing me to access the volume settings. Need help guys. Thanks.

brought to you by my not so sexy GS4 MF3