Sudden loss of audio on Elitebook 840 G4

[galapogos]

Hi,

I have suddenly lost audio on my Elitebook 840 G4 after a Windows 10 BSOD, upon reboot.

I got a popup message  "A conexant audio device could not be found. The application will now exit." and there's a red X in my taskbar's speaker icon.

I googled and did the steps stated in https://h30434.www3.hp.com/t5/Notebook-Audio/A-Conexant-audio-device-could-not-be-found-The-applicat... which are the following:

Download and install the latest Conexant driver (http://ftp.hp.com/pub/softpaq/sp85001-85500/sp85090.exe)

Reboot

Run C:\Program Files\CONEXANT\SA3\HP-NB-AIO\setup64.exe and let it UPGRADE.

Reboot

Run the sound troubleshooter

This did NOT fix the problems as I got "Troubleshooting couldn't identify the problem"

I'm still not getting sound, and "Sound, Video and game controllers" is also still missing from the device manager.

How can I fix this?

[galapogos]

I googled a bit more and came across this page at https://www.drivereasy.com/knowledge/solved-issue-failed-to-create-conexant-audio-factory-the-smarta...

It suggests that CxUtilSvc may not be running in services.msc. Well, my services.msc does not even have CxUtilSvc installed, and I don't see it in my C:\ either, though I do seem to remember seeing this folder in C:\ previously.

This service/folder is missing despite re-installing the latest drivers from the HP website.

How can I restore the CxUtilSvc?

[galapogos]

Now my C:\Program Files\Conexant folder just disappeared. Reinstalling the latest HP drivers shows a success, but still no folder. What is going on?