I have two jets each with a 40/24. They both work great and I purchased them a few years ago second hand with each aircraft.
One of them when you plug the MPX leads in from the battery, the Champion powers up immediately whereas the other one in the other jet only power up after plug in when you turn them on via the switches.
I assume this is a programming thing but I cant seem to find reference to it anywhere. I want the Champion 40/24 to stay off when I connect the battery leads as default if possible. Seems strange both units are different.