Dell U2711 stay black or wont Power on

• 1. Pull the powerplug out.
• 2. Hold on the Power-Button to get a full discharge (about 10 Sec.)
• 3. Reconnect powerplug.

https://www.dell.com/community/Monitors/Dell-u2711-displayport-problem-quot-entering-power-save-mode/m-p/3546231#M79287