P3A: Minor crash. Now one motor won't start.

[Vertigo]

I'm not seeing any signal on the motor that is "down".

I wouldnt necessarily expect any signal if the motor is defective (or wire/connector/whatever broken). Like I said earlier, ESC like these requires a working motor as it uses its back emf to determine the position of the motor. If cant get measure any, I dont know what it would do. Quite possibly nothing.

If does turn out to be the ESC; I assume you inspected it visually, and there is nothing that looks burnt? Ive seen threads where people repaired the ESC(s) with a reflow gun, but I wouldnt know what to replace.

 

[indoctrin8ed]

Vertigo, I set my scope to trigger on a voltage higher than 0.25 volts then capture the next 1 second. Nothing happens. Starting up the motor has to start with some input voltage. I suppose if it's an open circuit then the motor controller could sense that and not even try. So your point is valid and I look forward to seeing what this turns out to be. As my newb knowledge on these style of ESCs, they measure the inductive current fed back through the other windings to determine position of the motor - so the motor has to turn first for that to happen, and in order to turn, it has to be energized - and I don't see that signal on the black/red at all. Again, I'm just guessing. Half the fun of being a hobbyist is exploring these scenarios, though I'd just like to get the thing working before the July 4 weekend.

As far as "ESC" - I see nothing on the board that indicates burns or damage, though I did not look underneath the board. Everything looks normal visually.

 

[indoctrin8ed]

Hunch: I get about 0.6 ohms for all motors, including the "bad" one.

 

[indoctrin8ed]

Quick update - I ordered replacement motors but wont have time to install until next week. I purchased a Phantom 4 to get me through the weekend. I hope it's less fragile. I'm placing my bets (unfortunately) on the board being bad because the motor shows 0.6 ohms across all winding sets - which is normal and there is no signal on the scope from the ESC on startup. Will see if this turns out to be true or not.