problem

I just bought an HP z27 4k monitor but when I hook it up to my Windows computer, the screen keeps flickering.

solution

The solution for me was to change the resolution through the NVIDIA control panel.

• Open up NVIDIA Control Panel
• Navigate to Display > Change Resolution
• Select your HP z27 display
• In the Resolution picker, choose the "native" resolution which should be 3840 x 2160. Note: you should click on it even if it looks like it's already set to that.
• Once you've selected an option, an Apply button will appear. Click on that.

The screens should flash again and then your monitor should be fixed.