My motherboard model is Gigabyte M68MT-S2P says it is Compatible with AC'97 and Intel HD, But the front Audio panel doesn't seem to be working? There is only one header cable for the case, My case model is Casecom KM-6788 BLACK.
Hmm. I dont see it in your manual either.
Did you line up the case header so that the spot with the missing wire lines up with the motherbd headers' missing pin? (That would be pin 8 btw) If you have more than 1 missing wire then thats the ac97 header and your case should have both.