For some Case , when you press Remote controller to control beams up and down , it possible happen like "Up" button and beam uping, but when press "Down" ,the beam no reaction, what problem ? check the video first
Video translate as following:
-remove the Curtains of the post and find remote controller
-make sure the power connect well first
-another signal line as the video show , disassemble the "white" connector
-find Multimeter and setting value to "DC 200V"
-insert 2 Pointer of multimeter to the "white" connector
-press "remote controller" up button and see multimeters voltage
-multimeters voltage value is ±24V around means the remote controller working good
then checking motor