Hissy headphone socket, virus kc

[IB]

This is probably a hardware fault isnt it? The other outputs are fine but there is a lot of background noise coming from the headphone socket, even with the volume all the way down... Its been this way since i had it a couple years ago and never really bothered me too much but now im about to sell it, i need to know if it is a hardware fault. Would this be too difficult to get fixed outside of access as its not under warranty, or is there anything other than a hardware fault that would cause this? Thanks...