Hexart, I have a Gigabyte GA-Z77X-UD5H (rev. 1.0) board just like yourself and it has recently been giving me problems related to the audio. I'm now using the board under Linux, and the audio is very troublesome.
It has been five years now since Gigabyte asked you to remove your post with the hardware repair information. Would you consider re-posting the information now? People will have this board for many years to come and I don't think Gigabyte is going to care anymore about this issue.
Alternatively, if you are not willing to post the information publicly, could you privately send me the details? I'm very capable with a soldering iron and would love to fix this in hardware once and for all.
Thank you