2023 M2 Mac Mini internal speakers not working

If the audio is not reliable switching back to internal when a device is unplugged.

Then that sounds like a problem with the micro switch inside of the Mac mini's headphone port.

Sadly the only way to confirm and/or fix a bad micro switch in the headphone port.

Is to take the Mac mini to your local Apple Store or Apple Authorize Services Provider for service.

To find the nearest service provider, go to > Find Locations

It will help us get a good idea of what is causing your problem if you provide a report of your system, that way we do not have to play 20 questions with you. The report we are requesting does NOT provide any personal information and is extremely safe to use. Please navigate towww.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.

When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again. 

For instructions on how to download your EtreCheck report and attach it to your reply to this message please click How to use the Add Text Feature When Post… - Apple Community It is helpful to us if you download the report to your Desktop.

You're welcome.