Problem with speaker socket in Mob

[Morfinel]

When I plug speaker to my mob, sound output is only from one speaker, to get second one to work I need to twist cable around and it don't usually last, is there easy way to fix it, I have custom case and don't have front speaker outlet.I tried to connect one from my previous case but it might be broken, there was lots of rattling and no sound. Any idea if it's easy to fix, or if I can connect it to other socket, there are 6 I think in total, or buy extension to connect with mob. I don't think there is point to RMA this mobo

Thanks

 

[RJC]

It may be easier if you have a spare PCI (e) slots to buy a separate sound card and disable the onboard sound.

(I assume the speaker cable is ok)