How to test a motor arm whilst still attached to a drone

[MA1_Newbie]

As per title, is there a way of testing/spinning a motor arm whilst still attached/welded to the board? Never done this but before replacing arms I wanted to make sure its the arm that is questionable hence wanted to see if there is a way of testing it.

I see on a Mavic Air (first gen) each arm has 3 cables (red, black, white) not sure which ones will spin it, and I have a DC power supply if it helps, or am I on the wrong track?

Thanks in advance.

 

[Kilrah]

each arm has 3 cables (red, black, white) not sure which ones will spin it

They just connect to the motor directly, so you could use a standard standalone brushless ESC .

 

[Droning on and on...]

These are brushless DC motors that require an ESC to operate. They do not work like a simple DC motor that produce a torque with a simple DC input. There are three wires because an overlapping PWM signal must be energized on individual windings in the motor to make it spin. In a BLDC, the magnets are on the armature, and the stator contains the windings. The ESC produces a magnetic field in the stator windings that moves from winding to winding around the circumference of the stator, and the magnets in the armature are attracted to it and follow it around and around.

So you can't just hook up a power supply to the motor leads and have it spin. The switching action the commutator performs in a traditional DC motor is done electronically by the ESC.