Hi, we might be using similar devices, and have the same issue. I installed the latest Zorin Lite version on an old Acer S1002 (2gb ram, 30gb storage), the keyboard dock was pretty much useless but the tablet part was still working...just, very slow on Windows and had a tendency to randomly restart.
So i tried a bunch of "lite" linux OS, and so far, Lubuntu and Zorin Lite seems to be the best fit for me. I prefer Zorin because it seems to be more responsive/faster, but on Lubuntu everything seems to be working perfectly fine (including audio).
Anyway, i picked Zorin Lite and have been using it for a few months now and have been too lazy to search/learn a solution for this audio issue..until now. I somehow stumbled on a band-aid solution for the audio issue on my own - using Bluetooth audio devices. For some reason if i start playing a video on MPV..and then connect my Bluetooth headphones...Audio output works! But only on the Bluetooth headphones..internal speakers and the 3.5mm jack output are still not detected.
I'm not a technical guy,..so if someone has a better/more permanent solution to this issue, I'd be very interested.