Diagnosis
A completely dead controller with a desk that has power means the issue is either with the controller's connection or its internal wiring. The control box has power (since the desk holds a position), but the signal isn't getting through.
How to Fix It
Unplug the desk from the wall outlet. This is crucial for safety. Crawl under and locate the small rectangular control box mounted on the underside of the frame. Find the thin wire that runs from the hand control to the box. Firmly disconnect that plug and then reconnect it, making sure it clicks in. Check the wire itself for any obvious pinches or damage, especially where it enters the hand control. Plug the desk back in. If lights come on, you're set.
If That Didn't Work
If it's still dead, the hand control itself may have failed. You can try a very basic test: with the desk plugged in, gently wiggle the wire where it meets the hand control while pressing a button. If a light flickers, the wire is broken inside the controller casing and the whole unit needs replacement from Autonomous.
Heads Up
Don't try to open the hand control or control box. They're not user-serviceable. If re-seating connections doesn't work, you'll need a replacement part from support. They'll ask for your desk's serial number, found on the underside of the desktop or on the control box.