QUESTION : When I turn on the power (via wall switch), the fan runs at the highest speed and cannot be controlled via the remote control.

ANSWER : Check the connections, it seems that the ceiling mount clip is connected directly to the fan.

QUESTION : When I want to check the power connection of my DC fan, the motor jerks and does not respond to the remote control.

ANSWER : Only when your DC ceiling fan is completely assembled (including blades) will the motor work properly and connect to the remote control.