No audio devices found!

I'm running a MacBook Pro late 2013 on Sierra 10.12.6.

I was using an external sound card to record audio and then my MacBook died. When I restarted the computer there was no built in audio playing. When i went to System Preferences > Sound, where it usually says the name and type of built in audio device mine just says 'No output devices found'

I have tried:

plugging in headphones to try to wake it up

Plugging in a USB soundcard to try to wake it up

booting in safe mode

Resetting the PRAM

Resetting the SMC

Update to last supplemental version of OS

Running in another user account to test

Ive tired some terminal stuff that i found online but can't remember exactly so if anyone wants to share any info on that, that would be helpful also.

I have noticed in System information that my built in device is not there either, im not sure how?

im confident this is a software/driver issue and not a hardware issue as everything was working fine up until my MacBook died.

Any help at at this stage would be massively appreciated!