Screen Flicker on Extended Monitor If Set to Duplicate Built-in Display on Laptop

• Screen goes on and off while using an HDMI cable.
• Setting up a duplicate display could be difficult in terms of port compatibility and refresh rate limitation. 
• The refresh rate between the primary display and the extended display are not the same.

How to resolve flickering issues on the extended monitor.

1. Open the Start Menu and choose Settings
2. Navigate to Display Settings
3. Click on Advanced Display Settings
4. From the list of options, select your external display monitor (model may vary)
5. Choose a refresh rate of 30.000Hz or higher

If the issue persists, Contact your laptop's original equipment manufacturer (OEM).