Possible problem: Mains not connected to the control box
Try/Solution: Try to connect a lamp or similar to the mains supply to check whether there is adequate supply voltage.
Possible problem: Are plugs mounted correctly in the control box or to the leg?
Try/Solution: Check all connections.
Possible problem: Are there any visible damages on cables, controls, the control box or legs?
Try/Solution: Damaged parts must be exchanged. Contact the company that sold you the desk.