How to see MAVlink messages related to arming failure?

Hi all-

I’m at the point where arming on my PX4-equipped quad is failing and I cannot figure out why. I keep seeing references to messages (I believe MAVlink messages) about arming failures but I can’t figure out how to request/see them! I’ve been able to calibrate everything I think I need to via Qgroundcontrol, I have a fully charged battery, a good GPS lock…but I can’t seem to arm for flight or, before that- motor testing.

I can’t tell you how happy i was to find (audio) explanations for the plethora of sounds I’m hearing! Thanks to that now I know for sure that I have a GPS fix, but am not armed. The only questions are: why not? what pre-flight check is not passing?

thanks in advance-
Patrick