beam gen 2 microphone

Depends, most likely, on why it won’t come on. The first thing I’d do is a simple reboot of the device, by unplugging it from the wall for two minutes, then plugging it back in. This will force a reload of the OS. I’d also check from within the Sonos controller for any updates there may be, and apply them. 

If neither of those work, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution. And it may show a hardware fault, something this community can’t see. 

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

It appear that the “microphone on” LED on the Beam only lights up when there is a “voice app” enabled in the controller app on my IPhone. When I enabled the Sonos voice app in the controller the light came on. I think the “microphone on” LED is only intended to indicate that the Beam is ready for receiving voice commands. When it comes to any microphone use required by TruePlay I presume the microphones are turned on by the Sonos system when needed.