Minimum connections for Pixhawk to function?

Hi All
Does anyone know if there is a minimum set of things that must be connected to a Pixhawk for it to work normally? I’m trying to use a pair of them without any motors connected and they don’t seem to really “wake up”. The Pi can see them as connected peripherals, but can’t see what version of ArduSub they are running, attempting to update ArduSub doesn’t work and QGC never connects to them. These are “factory fresh” units.

I don’t get any life from the Pixhawk when connected directly to the PC via USB, either, although the pattern of its lights changes-- I do now see what I think is a blue heartbeat light and the I/O and IMU B/E lights aren’t on anymore. Still nothing from QGC, though, and no ability to check or load firmware.

Here’s what the LEDs mean: LED Meanings · PX4 v1.9.0 User Guide

If you’re not getting a connection when directly connected to a PC via USB, its probably just dead. If it came from us and has some sort of sticker on the bottom, it means we checked it and loaded ArduSub. Something my have broken in shipping is all I can think of.

Send us an e-mail to support@bluerobotics.com and we can get you a new one.

Hi Kevin, thanks for the info. As you suspected it seems like one out of the two Pixhawks I got recently is just a dud for some reason, the other one works just fine when hooked up to just a camera servo and leak sensor. RMA?

I’d recommend just RMAing it.