Win10 update broke computer speaker

Windows 10 Home

The September update disconnected my Logitech Z337 computer speakers. When I turn it on, the speaker icon says "no speaker connected". The driver is up to date, and the speaker appears in Control Panel. Sometimes, the speakers will start working, but next time I turn them on I get the same error message. The speakers are connected and functional, so the problem is in Windows settings somewhere.

I had a similar problem after a previous update, and my printer didn't work for weeks. Apparently there is something wrong in the registry, but I don't know what.

How can I get Windows to recognize my speakers?

Note : under Sound Device it says "Realtek HIgh Definition Audio"

[QUOTE=f14tomcat;2018341]Make sure under Settings>Sound that entry there matches. There's a drop-down arrow of choices. Also, on same page is an option to run the Troubleshooter to see if it finds anything amiss.

Tom
Thanks for the suggestion. In the box for Choose Your Output Device it says "no output devices found". But in Control Panel the Logitech Z337 icon is displayed. Apparently, after the last update, Windows no longer automatically recognizes the speakers as default devices. Ironically, after some time has passed, I sometimes discover that the speaker icon in Taskbar has changed, and the speakers are working again.

Previously, the Troubleshooter found nothing wrong with the speakers. But this time, it said the speakers were disabled, and offered to enable them. Yet after the enable, the speakers still don't work. So it referred me to an agent. If it's a non-human agent, I don't expect much help. That may take some time.

Later : The "agent" referred me to an FAQ list. Which suggested setting the speakers as Default Device. But in Control Panel the Logitech speaker is X-ed out, and I can't select it to set as Default.

Meanwhile, any other ideas?