09-11-2019 12:41 PM - edited 09-12-2019 01:04 AM
So, earlier today I think my laptop reset itself ("bugcheck") - I'd left it on while doing chores, so only saw after power-up - and after that I just didn't have the RealTekHD Audio thing, or anything at all under the "Sound Controllers" section. (the speaker also showed the issue)
Of course, the first thing I tried was the Windows troubleshooter (the one you access by right-clicking the speaker icon), but that hung on "scanning for hardware changes".
The Intel SST OED device under "System Devices" showed some sort of power error (I can't remember the code), so I attempted to disable it. At which point the Device Manager crashed. The SST OED Device did and does seem to show as disabled, but it took a while to get everything to show it as such, and now it can't be enabled.
I attempted to do a system refresh, but that hung for a sufficiently long amount of time that I thought it ran into an issue, so I decided to try to restart windows to the advanced boot options using the settings menu. This also didn't work - at some point during the restart there was just a crash, and then windows booted normally.
I then did the troubleshooter with HP Support Assistant, but a lot of the steps were the ones that I'd tried previously (or assumed the existence of a RealTek Audio HD Device). The first one I hadn't (I think - the support chatbot is having issues) was using the Recovery Manager and installing the RealTek Audio HD Driver that way - I am currently in the process of trying that, but it's taking a lot longer than driver installation normally does in my experience; it's been an hour now, easily, and it's still going (maybe; one bit of feedback for that particular program that there needs to be more visibility of system status).
For potential causes: I did install a big Windows update a couple of days ago and, foolishly, deleted Windows.old after a day, because it was using up 40GB (I have enough hard drive space that it wasn't, in fact, a worry, even if it was a big chunk). I also installed new audio drivers after said update - I had an audio delay issue, where when a stream of audio started it would take a few seconds for it to actually start, and updating the drivers seemed to help at the time.
Note that it was working fine this morning as far as I can tell.
Looking at the Event Log, just before the anomalous shutdown (around 13:52, though I can't find the relevant event now) IntcAudioBus had whatever the event with ID 17 is - it did so after the two most recent cycles (14:06 because I did indeed try turning it off and on again, and 17:18) - and IntcOED went through whatever its event ID 2 is (the description cannot be found) four times over. The latter stopped once I disabled the SST OED device.
Edited to add: I did also try installing the Hardware Diagnostics UEFI, but creating the system restore point took a suspiciously long time (this was I think before the later restart). If the driver reinstallation is actually working, I don't think attempting to do that installation now would be a good idea, but I'm happy to accept a contrary suggestion.
Update: It seems like the reason for the hold-up was creating a system restore point - I left it running while eating dinner, came back to it having restarted. The SST OED is back (well, it's enabled, but it's still suffering Code 10), as are its errors (which are actually on start-up). Looking in the event log, a minute or so before the apparent restart time - 20:18 BST - there was an error to do with not being able to create a system restore point while the driver was being installed. There's just a really long time-out or something.
I don't know how relevant it is, but I have a LOT of errors from the Bonjour Service, too (wide variety of text, all Event ID 100).
UPDATE (Same day, 22:09 BST): I was able to reset my PC by force-shutting it down, then restarting from the login screen while holding shift to get to the recovery options (this just takes you straight to it, because Windows hasn't booted yet I guess?). Then I did the reset my PC thing and that seemed to cause the audio problem to resolve itself - I'm going to just do another restart now to check for certain.
Update (next day, 08:02 BST): Yep, everything seems to work fine now. Leaving this post up in the hopes it helps others facing this issue.