audio device isn't set as default, can't make it default

Hi all, Windows 7 Home Premium x64 on HP-DM1-4050us laptop, disabled a couple of unneeded services, now headphones not working, no idea which service caused this but I didn't touch either of the two required audio services (Windows Audio, Windows Audio Endpoint Builder).

Audio now plays fine through speakers, but plug headphones in and it's mute. Headphones work fine with other audio devices like my phone, though. Triple checked I'm using the right jack and plugging in completely.

I ran the Audio troubleshooting wizard, and it appears the problem is that there are two devices, "Speakers and Headphones" and "Communications Headphones", and the former is the default audio device, the latter is the default communications device, when the latter needs to be both.

However, right clicking the latter device and hitting "Make Default Audio Device" has no effect, the former option remains the default audio device. Anyone know what the problem is here, why the default audio device can't be changed, or what windows service could have anything to do with this (besides the two primary audio services)?

Audio devices:
https://i.imgur.com/8SPJ9.png

Troubleshooter results:
https://i.imgur.com/5FRYc.png

Thanks!

Have you installed drivers for your audio?

Yes, drivers installed, no yellow ? in device manager, audio works fine when headphones not plugged in. Driver name in my Audio Devices screenshot - IDT High Definition Audio Codec.

So instead of trial-and-error restoring each service I disabled, restarting after each and testing headphone sound, I just restored Win7 from a recent disk image instead (like a 1-day old image, so nothing was lost).

Headphone sound now works again, and I've learned my lesson about fiddling with services, for now at least. But fwiw I'm 99.999% certain this breakage was caused by me disabling a service that has some non-obvious connection to the headphone sound.

Fwiw here's the list of services I disabled. It's a list for Windows XP, so I disabled most of the ones that were identical on Windows 7 and ignored the others. One of them broke my headphones. (and here's a better list with explanations of each service, which might help troubleshoot which one affected headphone audio).

Even when broken, the Audio control panel could recognize when headphones were plugged in or removed, and changed state to reflect that. And it could play sounds on the headphone channel, as evidenced by the sound Tests actually causing the sound bar for the headphones to fluctuate. But it just didn't actually make it to the headphones.

Anyway, hopefully anyone else who comes across this looking for a solution might be able to investigate this as a services issue and find the solution. But best solution ime is, keep regularly updated full disk images that you can restore to.

Update: Broken again, same problem. After getting it working, restarted the computer later, and problem is back. Uhg. Wtf.

Only thing I can think of is an automatic Windows Update broke the driver. Unfortunately I uninstalled the IDT device driver to see if Windows would reinstall a working one automatically (as another forum suggested), before realizing I should have tried rolling it back first.

If I can't find a solution, will reinstall the image and disable all Windows Updates to see if that prevents a regressed driver from installing over a working one.

Images of the Windows Troubleshooter being unable to set the 'Communications Headphones' as the default device:

Update: Fixed itself somehow. I logged off and it was broken, logged back in the next day and it was fixed. Wtf. I give up.

Thanks Layback, yeah I figured out not to tweak Win 7 the hard way :) Won't make that mistake again.

You know what ... I'm experiecing the same problem and it's getting on my nerves. I could fix it prevously by plugging and un-plugging the headphone ... today it doesn't solve. Both headphone and internal speaker of my laptop playback the audio at the same thing when it should have been only headphone when headphone is plugged. The similarity between my system and yours ... win 7, and that lousy IDT Independent (RTC) headphone. This is so frustrating when I needed to do a recording by tonight, ... sigh.