Pro 24 All-in-One Plus QB24250, microphone problem

Clarify. Do you mean that after you plug in an external USB desk microphone, that the built-in retractable camera left and right microphones are still active?

If yes, did you open System > Sound > Input and select the external USB desk microphone under, "Choose a device for speaking or recording" as the Default Device?

Sorry if I wasn't clear. I use a plugin desk microphone with Zoom, and on my old Optiplex I turned off the microphone with the button on the mike itself. This disabled the mike entirely. Now on my new QB24250 it doesn't and the sound is still transmitted via Zoom. The desk mike is set as the default so the mike in the PC won't be active, any more than it was on the old PC. I've checked doing a test in Microphone Settings in Windows11 and the default plugin mike is still active even when turned off. Does this make sense?

Doesn't make sense to me either.

"turned off the microphone with the button on the mike itself"
If turned off using the button, how can it still receive voice input? What specific desk mic model?

It's a TKGOU model um6 which, as I mentioned, worked correctly with my old Optiplex AIO. So something has changed in the way USB ports handle external equipment between that and the new QB24250.

I've still got the old Opteplex and I tried the mike again on that. It works correctly.

Unknown. Perhaps time to test a new desktop microphone.

I thought you might say that! Still, it was worth asking for ideas.

Thank you anyway.

You might have better luck with a microphone with an actual mechanical switch and/or one that plugs into the audio jack.

Thanks Brad. I'll do that.

Mike

Which one?

I’ll try the mechanical switch as I’m not sure my pc has a audio jack.

Dell Pro 24 All-in-One Plus QB24250 Owner's Manual (Ports)

There's an audio jack for both headphones and microphones on the left side.  I'd avoid it for microphone use.  I've seen too many complaints about single combo jacks (various models) not working for the microphone.  Difficult to diagnose.  As long as USB works for you, I'd stick with it.  Sounds like what you plan on anyway.

@DELL-ChrisM2​  Is the plugin desk microphone with Zoom USB?

Yes, I have used the retractable mics on the camera for Zoom but I need to be able to mute when I'n not contributing to a discussion. Hence the use of a desktop mic with a switch. And yes, the plugin mic with Zoom is a USB connection.

Before commiting to buying a new mic I'm going to try another USB mic of a different make, lent to me by a friend, to see if that has the same problem.

I'll report back.

Thanks to you both for your help.