No left speaker sound after Windows 7 install Realtek Azalia ALC1200

Issue: no sound in left speaker after installing Windows 7 64-bit

setup: Asus M3A-H/HDMI motherboard with Realtek "Azalia" ALC1200 onboard HD audio
Philco stereo (basic stereo system, with rear "CD in" mini stereo input jack

(this board has HDMI audio out, a separate S/PDIF out port, plus 6 traditional mini
headphone type jacks. Of these 6, there is an orange for center/subwoofer, black for rear
speaker out, light blue for line in, lime for headphone or speaker<becomes front speaker
out in 4,6 or 8 channel config>, pink microphone, and grey for side speakers in an 8
channel setup)

Under Windows XP, there were initially several issues I had getting the sound to work properly. For example, if you installed the multi driver/chipset install from the included motherboard driver CD, you got absolutely no sound at all. The fix from ASUS was to format your hard drive, and then install your sound drivers first. (in other words, not use the multi install program they had provided on the CD, and not install the drivers manually in the order they had it set to do) They never, as far as I know, bothered to fix the multi install so that the sound driver installed first. It was a horrid issue that should have been caught before they shipped the motherboard.

That said, there were still troubleshooting issues at first under XP. For one, 3 or 4 times a week, the system would tell me that something had been plugged in or unplugged from a port. (when I had done nothing) I changed the cables, connected and disconnected them, and it still continued. (yes, thank you oh so much for giving this thing the "smarts" to know when a cable is plugged in or unplugged) I ended up having to disable the digital output, since that was the default selection. Disabling this enabled me to use my regular stereo speakers. However, for some reason I had to hook them up to the black port to get stereo. (this is supposed to be rear speakers in a multi speaker setup) This worked ok for the past couple of years - all I need is basic stereo.

Now that I've installed Windows 7 64-bit version, I can no longer get any sound from the black port. The only thing I am able to get is right speaker sound from the lime port. The system seems to think that everything is set up and working properly, but when I test the left speakers, I hear absolutely nothing. Frankly, I find myself wishing I had a standard AC '97 sound chip on here, with line in, microphone, and 1 speaker out jack - I think it would be a lot simpler.

Troubleshooting steps:

First thing I did was to hook up a pair of headphones, and try to replicate the problem. Yes, I only get sound in the right ear of the headphones, just as I am with my stereo. No sound seems to come from any jack other than the lime green one, where I get right speaker sound only. Ok, so that would seem to indicate that there is no problem with the cable connecting the computer to the stereo, and no problem with the stereo itself, the speaker wires, or the speakers. (unlikely anyway, since I had stereo sound until installing Windows 7) Since the headphones have the same issue, I reason that the problem must be either with the motherboard, or else the sound driver.

I booted into the BIOS, and made sure that there wasn't a setting that might be messing up the audio. The only choices for the "Azalia" onboard audio were "disable", and "auto", which I guess means auto detect. I'm guessing that the disable is meant to use if you add on a discrete sound card to the system, so I left it set to auto

Next, I went to the Asus website to see if they had an updated Windows 7 sound driver. Nope.

So then I went to the Realtek website, and they do not have a specific ALC1200 driver for that board. Instead, they have a generic "HD Audio Driver" download that is supposed to encompass all of their "HD AUDIO" motherboard onboard audio chipsets. I decided to give it a try.

After installing the Realtek drivers, I noticed that the provider listed in device manager was Microsoft, not Realtek, and the date was sometime back in July - not October, which was when the Realtek drivers were released. I manually removed the devices, uninstalled then reinstalled the Realtek drivers, and rebooted.

Now I still only have sound in my right speaker. In Device Manager, this is what I see: under "sound, video and game controllers", I see two speakers. One is labelled "High Definition Audio Device" - driver provided by Microsoft, date July 13 2009, version 6.1.7600.16385. It says it is working properly. The second speaker I see says "Realtek High Definition Audio" - driver provided by Realtek, date October 6 2009, version 6.0.1.5953. It also says it is working properly.

I'm not sure where to go from here. I'm pretty sure I don't need to replace my old stereo, as I had originally thought. It seems to work fine when I am listening to the radio on it, and when I hook up an MP3 player to the audio in jack on the back, I hear the music in both speakers.

Either the driver is not working properly, there is a setting I need to change somewhere to get stereo, or else the motherboard is defective.

I wouldn't bother with it much, except some of the games my kids play have stereo, and you can't hear the character talking on the left audio track. That makes it impossible to play the game, since the left audio track gives them hints. Also, some songs I have played just sound strange, without the left vocals.

Anyone have any suggestions? Yes, I've also done Windows update, but that doesn't make any difference either.

I had a similar problem with my asus M4A77TD and windows 7 64-bit - only the right channel produced any sound.

I managed to get it working by changing the 'sample rate' in the 'speaker properties' dialogue (advanced tab). (Tip - click on the speaker icon on your windows toolbar and then click on the speaker icon at the top of the pop-up volume slider) Any change worked, and on changing it back, it still works. It has since failed again once but this fix got it working again.

Does this work for you? I note that there's some new audio drivers now for my sound card. I'll try installing them if the problem recurs.