Audio Interface issue with new Mackie Onyx 12 mixer - No sound from monitors/registering on board.


New Member
Hey, this is a possible Mackie or MacOS issue more than a Logic issue per se, but I figured you all might spot what I'm missing.

I'm replacing my old Mackie Onyx 1620i we've used for over 10 years with a Mackie Onyx 12.
I've been very happy with the 1620i, but Apple doesn't support firewire from MacOS13, Ventura, onward.
So I figured I'd stick with the same make, new model.

So I've hooked up the same mixer, but no sound is coming out of the studio monitors and, on the new board, the meters for the main don't register anything (not even the lowest level of green lights).
The computer sees the new board, and I can select it in System Preferences -> Sound.
I also made sure that the board is selected under Logic Pro -> Settings -> Audio -> Devices
I've gone back and made sure the new board's firmware is up to date (version 1.1.17 per the Mackie site).
PLUS, I still have the old board, and it plays through the studio monitors (and registers on the main meters) just fine.

Part of me feels like I might be missing something fundamental. Any suggestions?
For anyone interested, it was something fundamental... and reading the correct part of the manual three times is the charm, pages 5 and 9 for this Onyx mixer to be precise.
The solution here is making sure the "L/R" button on each channel is depressed in the 'On' position (i.e., any channels you have mics/instruments in as well as channels for playback).
My old Onyx miser is different, but reading is fundamental, kids! :D