Intermittent motor failure driving me crazy. Motor 3 on my racing quad randomly stops mid-flight, then works fine on next power cycle. One or more motors spinning intermittently can indicate multiple root causes. If motor still doesn't spin after replacement, the problem is most likely a damaged ESC - varies greatly depending on ESC type used. How do I definitively determine if it's the motor or ESC without swapping expensive parts? Need to verify flight controller software shows correct motor numbering and ESC protocol (PWM, DShot) - incorrect protocols cause communication failures.

An oscilloscope would really help track down the problem - you could see if control signal reaches the FET and whether the FET is working. Without scope, swap the motor to different ESC channel and see if problem follows the motor or stays with the channel.

Use multimeter to measure motor winding resistance and compare to normal values to determine if windings function correctly. Also check for frayed or broken motor wires and corrosion - replace damaged wires for reliable connectivity. Simple electrical checks first before assuming ESC failure.

Intermittent failures are the worst! Motors frequently throwing errors or losing ESC connection despite ESC troubleshooting indicates deeper motor issues requiring replacement. Could also be thermal - does it happen after extended flight time when components heat up? Check solder joints on ESC too.