This problem is driving me nuts.
I just got an Acer Aspire M5-481PT.
The audio wasn't working out of the box. The error message I see when I mouse over the audio icon is: "No Audio Output Device is Installed." I don't get audio from the onboard speakers and no audio from the headphone jack.
I tried updating the audio drivers and still no luck.
I deleted the audio drivers and rebooted. Again no luck.
But here is where things get interesting. The audio works if I plug in a USB headset or HDMI cable.
I even re-installed the entire system from a flash drive. Again, no luck. Does anyone have any suggestions before I send this back to Acer?
I'm running Windows 8.