Diagnosis
This points to a failure in the low-voltage wiring between the control box and the keypad, or a dead keypad itself. The motors get main power, but the brains (the keypad) talk to the control box via a thin cable.
How to Fix It
First, check the obvious: trace the thin, round cable that runs from the keypad down the leg to the control box (the black box often attached to one leg). Make sure it's firmly plugged in at both ends—into the keypad and into the port on the control box. Unplug and replug both connections. This connection can work loose during assembly or movement.
If That Didn't Work
If the connections are good, the keypad or its cable is likely faulty. The keypad is a single unit with a fixed cable. Branch support can send you a replacement keypad. Swapping it is easy: unplug the old one from the control box, thread the new cable through the same path, and plug it in. No tools needed.
Heads Up
Don't try to bypass the keypad or hotwire the motors. The control box needs the keypad's signal to operate safely. Running the motors directly without the control logic can make them run uncontrollably and damage the mechanism or crush something.