Motor "Spin" test
Before you undertake any repairs, conduct a motor spin test to identify which motors are spinning and which are not.
To do the spin test you'll have to go outside and go through the Preflight Check and then try to takeoff (WITHOUT PROPELLERS):
1. Go outside, power on AirLeash, power on Airdog, wait for a GPS lock.
2. Do the Preflight Check for Airdog and then AirLeash (if asked).
3. When you see the READY status on the AirLeash display, initiate takeoff (WITHOUT PROPELLERS) and check if all four motors are spinning.