I'm on an ancient MacBook (OS X Ver 10.9.5) from 2010, using a Zoom H6 Handheld recorder for my interface. Earlier this year, everything was a breeze when connecting a microphone through the Zoom, audio levels were happening on tracks, very straightforward; when connecting yesterday and since, the Zoom is recognized, but no audio levels show (or sound) on a given track. I've started and re started, checked mic cables, when using a condenser am sure that it is receiving phantom power, have it off when trying a dynamic mic, changed my usb connection from port to laptop (knowing it is "reads" the Zoom already, that THAT likely doesn't matter) So, I'm stuck! Zoom says driver updates are not needed for Mac products and I'm out of ideas (time, energy) what could I be missing, or need to try? (other than if the pockets were deep, a new Mac wouldn't hurt in all likely hood.)

Did anything get automatically updated? Are automatic System updates turned off? If nothing on the Mac changed -- and since the Mac still sees the Zoom -- maybe something in the Zoom itself changed -- maybe it was accidentally reset to defaults you'd changed long ago, or maybe a level adjustment or routing assignment was accidentally altered..?

I think I've looked at those things, but will do so again; pretty frustrating when you HAVEN'T touched a thing (I think : )