The LA34 Actuator, Hand Switch, and DC cord (not shown) from the Power Supply all plug into the CB9 Control Box.
If you hear a hum when the hand switch is pressed it indicates that the hand switch and the control box are working. All contacts are closing.
The hum could mean not enough power is getting to the Actuator, something is jammed, or the Actuator is bad. A meter will be needed to test for DC voltage and DC amperage. DC can be tested at the power supply V- and V+ terminals.
