I recently built a system with the following components:
Asus P8P67 Pro (updated)
nVidia GeForce GTX 560-Ti
Intel SSD, Samsung & WD hard drives
Corsair 600T case
Analog 5.1 speakers (with the three mini-jacks for front, rear, and center/sub)
Windows 7 SP 1, 64-bit
The system works very well and is very fast. I am pleased. However, I am trying to use the onboard Realtek HD Audio capabilities of the motherboard. The sound is working well in all regards (recognizing the insertion and removal of plugs in the various front and rear jacks, changing from stereo to 5.1 as requested, etc.) except that I am getting what seems like no sound but only soft electronic noise coming from the left-front channel (green jack) from the back panel plug.
I have confirmed the issue is NOT with the speakers: I have verified the front speakers work correct from the rear speaker plug. I have confirmed the rear speakers have the same issue when plugged into the front speakers plug. I have plugged headphones into the rear green jack and experienced the same problem with the left channel. I have plugged the headphones and speakers into the front panel jack and experienced correct sound in both channels.
I have removed and installed various Realtek HD Audio drivers: the drivers included on the Asus motherboard's CD, the drivers from Asus' website. The latest Realtek drivers from the Realtek website.
None of these driver changes/reinstallations correct the problem.
I submitted an issue to Asus and was sent a replacement motherboard. Last night I installed it... and had the very same problem. This leads me to believe the problem is not the motherboard but software-related.
The Device Manager listed multiple HD audio devices in addition to the Realtek HD Audio; I have learned they are introduced by the nVidia driver and I have uninstalled and disabling those devices and have reinstalled the nVidia driver. No effect on the left-front sound channel issue from the rear plug.
Late last night I was trying headphones in the rear jack and noticed that there IS some sound coming through, just very, very diminished and accompanied by quite a bit of electronic "glitching" noise that anecdotally seems related to video activity but really could be most anything, I suspect.
So, I believe I have eliminated the following possibilities:
-- The audio devices (speakers, headphones) are not the problem
-- The motherboard hardware is not the problem (unless this freak issue occurred identically on two boards)
Can you suggest other things I can try? My fallback plan is to install a discrete sound card, but I liked the ability to use the onboard sound for conveniences like the speakers being disabled when I plug headphones into the front.