M2P No2 ESC error after replacing motor and ESC board

[Fixitman1983]

I crashed my drone and had to replace the front right arm because of the no2 ESC error code. I also had some debris stuck in my front left motor. I replaced the front right arm and did a test flight and it was fine. I then opened up the motor for my front left arm to get e debris out and then got the no2 ESC error code again. This time though all my motors do the twitch thing when I power on my drone. I replaced my ESC board after this happened and it worked fine again. I was still getting a funny sound out of the front left arm and it wouldn’t start properly sometimes so I opened up its motor to check it. After putting it back together again I got the no2 ESC error code again. I’m guessing that opening up the motor heads while they are connected to the ESC board messes something up on the board because of the magnetics of the motor. But why does motor one (front left) affect motor two (front right) via the ESC board?

 

[bumper]

-snip-
I’m guessing that opening up the motor heads while they are connected to the ESC board messes something up on the board because of the magnetics of the motor. But why does motor one (front left) affect motor two (front right) via the ESC board?

Assuming you are disassembling the motor with power off, the ESC and on-board logic isn't monitoring anything. There are some mechanical things you might look at, though I'm unsure of what type of error a problem here would generate.

Remove props and turn rotor housings by hand - do they all feel the same with no gritty or grinding feel? Note there should be light pulses of increased resistance as the magnets in the rotor pass the ferrous rotor winding cores.

Run motors (without props), They should all sound the same (fairly quiet) and if you hold the body up and gently touch each arm near the motor, there should be no vibration. Now gently touch each prop shaft at its side near the top with your finger tip. If the shaft is bent it should be evident. If you have a dial or test indicator handy, alternately you could check runout with that while turning rotor housing by hand.