Diagnosis
The main battery is likely in a protective shutdown due to overheating or a voltage irregularity. The black screen confirms a complete power cut.
How to Fix It
First, remove the vacuum from the charging dock. Press and hold the power button for 15 seconds to perform a hard reset. Place it back on the dock. The screen should illuminate with a charging icon. Wait at least 30 minutes before attempting to use it.
If That Didn't Work
The issue may be the dock connection. Unplug the dock from the wall for 2 minutes. Inspect the metal charging contacts on both the vacuum and the dock for debris or corrosion. Clean them with a dry cloth. Re-plug the dock and re-seat the vacuum.
Heads Up
Continuous use on MAX suction for more than 15 minutes can trigger thermal protection. For large jobs, use Auto mode to manage battery temperature.