<< Solved >> Unable to play videos in Mojave while speakers are turned off

[Totti]

Quite possible the strangest issue I've ever had to deal with.

I spent literally days troubleshooting to see if it was an iGPU issue, QuickTime issue, VLC issue. And as it turns out, my system:
- Z170XUD5TH
-6600
-RX580
-AUDIOENGINE A2+ speakers

If I have the speakers plugged in but turned off, quicktime returns a 101 Unknown Error. VLC opens up a file but it freezes on a frame.

I can reboot with speakers off, same issue.
Turn speakers on, reboot, issue goes away.

Has anyone ever had anything even remotely similar ? USB is plugged in via USB.

It's surely related to not having an audio output device present, but why?

 

[Totti]

Solved: Was using Toleda's script without any issue since High Sierra came out, so I didn't think it could be anything to do with ALC.

I installed AppleHDA.kext and rebooted, voila. My monitor internal speakers detected and loaded, and all devices plugged in.

Even when not having any output on, videos still play. So there we have it.