Step 1: Remove the belts. Then turn on the board and scroll the wheel of the remote.
Step 2: If there is still noise, please check if the small screw of the motor gear is loose. (Screw size: 1.5mm)
Step 3: If the screws are not loose, please test the motors.
Step 4: Swap the connection of the two motors.
Here are 2 results:
1. If it's still the same motor making noise, that means the motor is broken.
2. If the original noisy motor doesn't make noise, that means the ESC is broken.
