Hello all! This is my first post here, sorry if i post in wrong area, also i'm Brazilian. I sell computer accessories, and i have sold about to 30 computer cases with ac'97 audio on front panel for a computer builder company. Now they are having a problem with the sound, and they are asking me what pattern is used on the computer case, because it seems to not follow default Front Panel I/O Connectivity Design Guide from intel (you can see at: http://www.formfactors.org/developer/specs/A2928604-005.pdf). this is the case connectors: The connectors uses a wire jumping pin 6 to 5 and jumping pin 9 to 10, but, doing a research over the internet, i can see that many computer cases uses this pin pattern, i found many images. Most of times, this scheme are used along with HD audio connectors, as a secondary option for non HD audio motherboards (like images below). but i still don't have any reference to this pin scheme. Someone have any idea how i can answer them about the pin usage, i need a trustworthy reference, they think this is a non-default scheme and are willing to send back the computer cases to me Thanks all and sorry for my english.