No sound on M90

Ok, I searched the forum and didn't find anything that helped me. Basically, I don't have any sound coming out of the speakers on my M90. I've tried pretty much everything I know... updated audio drivers, performed Windows Update, updated the BIOS, reset the BIOS, run a registry cleaner... but the speakers just won't output any sound. I still get sound out of the headphone jack though, which rules out the sound card being bad.

Thinking it was the speakers gone bad, I contacted Dell, who told me to run the diagnostics and answer "No" on the video test to trigger a system beep. He said that on the laptop, the system beep goes through the speakers rather than a PC speaker like on desktops. Not sure I believe that, but I did as instructed and sure enough, I heard the system beep. This would imply that it's not a speaker problem or a hardware issue at all. At this point, the Dell rep said the issue was likely with Windows. Just one problem... I also had Linux installed on the hard drive, and it has the same problem. In fact, in Ubuntu, the problems are worse... the media buttons don't work properly. Pushing the mute, vol up and vol down buttons bring up the OSD indicating said actions, but the volume (through headphones obviously) doesn't actually change. You have to actually do those actions from the desktop toolbar in order to change the volume.

The only explanation I can find is that the problem is in Windows. This may be showing up in Linux as well due to the fact that I had Ubuntu installed via Wubi, which places it inside the Windows partition. I'd prefer not to reinstall Windows, but I don't really see any other options at this point. If anyone has had a similar issue and can provide any help, I would appreciate it.

 

What happens if you boot to a Linux live CD? If those have sound card drivers, it'd be a good way to rule out Windows.

 

Actually, I haven't even thought of that. That's a good idea. I can't believe I didn't think of that.