The o/s is xp home sp3.
The motherboard is a winfast 760gxk8mb.
I have three line-out jack sockets:-
1) attached to the motherboard and positioned at the back of the computer,
2) at the front of the computer but, via a lead, plugged into the jack socket on the motherboard I described in 1) above and
3) at the back of the computer but positioned below the motherboard jack sockets.
All the sockets used to work but since i re-installed the o/s the socket 3) no longer works. The other two work ok.
I have looked (inexpertly) at the insides of the tower and the socket 3) seems to be attached to a separate circuit board - as if it was a miniature motherboard.
All the sockets on the motherboard agree with the schematics in the winfast 'users manual' that came with the computer and are working. The non-working sockets are not mentioned in the manual.
The non-working socket seems to be part of a collection of sockets that in total comprise (and are labelled):- (a) phone (b) line © mic (d) spk. it is (d) that doesn't work. I don't have a microphone, or i would have checked the 'mic' socket.
My feeling (for what it's worth) is that somehow the socket has been disabled - possibly in the bios settings - but I'm at a loss as to where to look.
I would appreciate any help that can be offered. Thank You.