Originally Posted by theothercliff
Sounds like M2 ESC's BEC is bad. I would test it out of circuit. With just a battery connected to it, check the voltage on the servo connector to see if it is correct. Compare it to the other ESC BEC voltages. If correct, test it directly connected to a junk receiver to see if it works.
Do any of these ESC's have switching BEC's? General testing here has it that switching BEC's don't like to be connected together. I have not verified this.
I already tried hooking up an other esc to the M2 port of the FC, with same result.
I don't know if the bec is switching... could be the case...
but if i would cut the bec wires on m2, 3 and 4, and just keep 1 hooked up, that should work, right?