Audio & Left side USB fail on Mackbook Air Mid 2013 Just wondering if anyone has any thoughts on the likely culprit for my mac that has decided to start being a pain in the ass.

Basically, the in-built audio has failed with both sound input and output displaying the "No Output Devices Found" message in the sound preferences screen. At the same time, the left side USB port (as looking at the device, under the magsafe port) also isn't working. 

I've tried:


PRAM/SMC reset
Trying headphones
Trying a USB headset (works on right side port, but seems to make the
mac try to recognise the in-built sound, which causes the whole
system to crash) 
Doing a complete fresh install of OSX (I know, extreme. And ineffective)


The system is fully updated. But based on the audio and left side USB port both failing, I suspect a hardware problem. 

Is it hardware? And if so, any suggestions on a fix other than taking it back to the apple store for expensive fix?
If trying to use the Audio Midi Setup (as suggested in comments by Tetsujin) doesn't help, your next step would be to run Apple Diagnostics.

Run Apple Diagnostics 

Follow the steps below to run Apple Diagnostics: 


Fully shut down your Mac 
Restart your Mac 
Immediately press the D key and keep it down until you see the Diagnostics screen appear 
Wait for Diagnostics to finish (this typically only takes a few minutes) 
Once complete, one of two things will appear on the screen: 


a No issues found message 
a brief description of any errors found plus further instructions 

If the diagnostics test does find errors, take a note of what they are 


Note: If pressing and holding the D key at Step 3 doesn't work, start again at Step 1 and, at Step 3 press and hold both the OptionD keys instead. This will try and run diagnostics from the internet instead, so you will need to allow more time for it to complete. Regardless, take a note of what happens and let me know how you went.