so i had a pretty decent tip-over on landing last week, hit a rock on the edge of my landing pad and the whole thing went sideways. anyway motor 3 is now doing this thing where it twitches when i arm it but doesnt spin up properly. the other 3 motors sound totally normal. i swapped the motor 3 signal wire to a known good ESC port and the twitching followed the motor, so i figured ok its the motor. but then i plugged a known good motor into the ESC 3 port and it also twitched a little. not as bad but still not right.

running 35A BlHeli_32 ESCs on a 5 inch freestyle build, motors are 2306 2450kv. ive reflashed the ESC firmware already and recalibrated. still doing it. could the crash have damaged both at the same time? or is there something else i should be checking, like maybe the FC output for that motor? im kind of going in circles at this point

the fact that a known good motor also twitches on that ESC port is your answer ? the ESC is toast, or at least one of the FETs took a hit. you can sometimes see it if you look closely at the ESC board, like a slightly scorched or discolored FET, but not always. i had the same thing happen after a concrete slam and the ESC looked totally fine visually but was giving me garbage output. replaced it and everything was clean again.

might also be worth checking your FC solder joints for that motor pad while youre in there. a hairline crack can do weird stuff that looks like an ESC problem but isnt. but honestly given the symptoms id just swap the ESC first, theyre usually the casualty in a side impact like that.

could also just be a damaged motor bell from the impact, like if it got slightly bent it'll cause weird commutation and the ESC freaks out trying to read the back EMF. ive seen that make a good ESC behave like a bad one. try spinning the motor slowly by hand with no power and feel for any grinding or roughness, if its super smooth its probably not that but worth checking before you start swapping parts