No Audio Devices after Updating BIOS

[wstrohm]

Well, my High Sierra Coffeelake computer ("Mini-ITX 3" below) was working fine, with sound, using Gigabyte's BIOS version F14a. But I read that they really recommend upgrading to their latest, F14 due to some "vulnerabilities." So I used QuickFlash to do that, which worked fine (I thought). Unfortunately, now there is no sound device shown in System Preferences or About this Mac/System Report/Audio (all is blank).

I downgraded back to F14a BIOS, but still no audio. So put F14 back in. No improvement, of course, but it seems something did in all my audio "devices." Now what? Hopefully I don't have to re-install mac OS 10.13.6, because Terminal is telling me it "can't find a helper" to complete my instruction to avoid an APFS installation.

Any advice or comments? Thanks for reading!

 

[P1LGRIM]

Clear CMOS.
Clear NVRAM.

 

[wstrohm]

Thanks, will try that now.

[Edit: Cleared CMOS, clicked the "NVRAM" icon in the OpenCore window, restarted: No change. No devices showing. IORegistry shows HDEF, but (see attached) no deep listing as was before.

 

[wstrohm]

Is there a problem with AppleALC.kext and Lilu.kext? It was working before I updated my Gigabyte BIOS from F14a to F14, which I have now done twice. (Going back to F14a didn't help.) Should I be looking at changing one or the other versions of Lilu.kext or AppleALC.kext in my OC 0.7.8 EFI? Do I need a brand-new OC 0.7.8 installation?

 

[wstrohm]

I found the problem (I think). Apparently my High Sierra installation (which was working perfectly until I updated the Gigabyte BIOS from version F14a to the final F14) has a bad AppleADA.kext file: See attachment. I have a "good" AppleADA.kext file copied from my other High Sierra computer, but I cannot replace the bad one since I am not "authorized" to mess with any files in my System folder.

How can I replace that file in System/Extensions? Some magic "sudo" Terminal command, maybe?

OpenCore Guide says this:

Checking AppleHDA is vanilla​

This section is mainly relevant for those who were replacing the stock AppleHDA with a custom one, this is going to verify whether or not yours is genuine:

sudo kextcache -i / && sudo kextcache -u /
This will check if the signature is valid for AppleHDA, if it's not then you're going to need to either get an original copy of AppleHDA for your system and replace it or update macOS(kexts will be cleaned out on updates). This will only happen when you're manually patched AppleHDA so if this is a fresh install it's highly unlikely you will have signature issues.

Result looks like this: