I had the same problem so what i did was go to https://www.acer.com/ac/en/CA/content/drivers Enter Serial # or SNID or model number of your computer then select '''Drivers and Manuals''', Click on '''Driver''' and download the '''Audio Driver''' for your computer and install the Driver.
Just plug In your mini-jack. A menu will pop up Realtek Audio Console, Which device did you plug in:
Line In
Mic In
Headphone
Speaker Out
Headset
Hope This Works For You