Based on your post #13 where you report 10 seconds of speaker sound:
I’d guess that some bluetooth audio device is connected. While connected the audio is directed there if you selected that option previously.
I have wired speakers and a bluetooth speaker.
Once I select bluetooth for ‘audio stream’ output, the wired output ends whenever the bluetooth device connects. It automagically restarts the speaker output when I turn the bluetooth speaker off after about 10 seconds of silence.
This behavior is due to the fact that I have my wired speakers chosen as my default audio ‘device’.
I use a KDE Linux desktop environment.
In KDE the audio setup is accomplished in system-settings -> audio.
*This is in the main System Settings in KDE, there may be many different volume controls and they may or may not be relevant or control the same specific audio settings.
I select bluetooth for specific ‘Playback Streams’ and it uses bluetooth when available.
Other desktop environments will have similar ‘features’ :-)
Check to make sure wired speakers are default ‘Device’
Check to see if you have bluetooth selected for any ‘Stream’
Try completely turning off the bluetooth radio/connection.
It is possible to have different things on different speakers at the same time too, it can be confusing when you get under the hood. Just work on one thing at a time and question assumptions.
Subdivide and conquer :-)
Well, before everything ‘crashed’, there was no problem using both the bluetooth earbuds and the speaker sound - everything would automatically switch to bluetooth as soon as the earbuds connected.
Now, even with new speakers (wired) sound doesn’t come out of the speakers, and now the bluetooth doesn’t work either..
We’re kind of afraid to do anything, since we screwed the whole computer trying to fix it in the first place :-)
We’ll just keep researching.
(We’re in an Ubuntu)