Help wanted with original Pixhawk

I was recently given a hexacopter with a Pixhawk and GPS unit identical to those depicted in the Wiki to set up for the beneficiary of a deceased modeller friend. Initial construction was never finished and the projected was abandoned years ago. Unfortunately I don’t know how to determine which actual version of Pixhawk it is (if there were more than one looking like this).

When I connected to Mission Planner I was advised to update the Arducopter firmware. When trying to do this I was presented with two initial options, “install firmware” and “install firmware legacy”. The wiki is silent on which of these to select or what the differences are. When selected, both show firmware version 4.2.1 as available. So I went with the first option and selected “Pixhawk 1” from the available list as this seemed to be the closest to what I thought my hardware is. This firmware allowed me to connect and to see information but I was not able to see any flight modes to choose from. So I figured I had installed a wrong firmware and went to the “legacy” alternative. This time all seemed OK and I did all the calibrations and setup according to the instructions in the Wiki (except for the “Initial parameter setup” part for which I can find no Wiki entry). The Pix can be armed with no alarms. However I get no motors running either with the motor test or upon arming. The ESC calibration step seems to work correctly (although the feedback for success is hard to hear).

I have made sure that the ESC control cables are in the correct slots in the Pixhawk (Main Out) and that the ESCs are battery powered. The radio calibration shows throttle activation correctly (although this should not affect motor operation in the motor test or on Arming).

I see that Servo 1-6 functions are 33-38 respectively in the FPL.

I haven’t used Arducopter for some years - since before the major changes - and memory fades so I am relying very much on the Wiki for setup help. Is there some step that I have neglected that is involved in getting motors operational?

Here: Initial Parameter Setup
Pixhawk1 is typically the correct firmware unless you have an older 1mb board. Then Pixhawk1-1M is correct.
Disable the Safety Switch (brd_safetyenable to 0) and try Motor Test again. No point in going further until Motor Test works.