problem

I have a Lenovo P1 Gen 2 and have been running Ubuntu happily for the last several months. Recently I updated a bunch of libraries and some firmware and my laptop would no longer connect to my external monitors. I ran xrandr in my terminal and even found that, when connected, Ubuntu didn't register the external monitors.

What's going on and how can I get Ubuntu to register the external monitors?

solution

The way I fixed this was to turn off Secure Boot. For whatever reason, Secure Boot was preventing my laptop from detecting the external monitors and then from showing anything on them.

I did this by:

• restart my computer
• press Enter to view more setup options when the Lenovo logo appears
• Select the Bios Setup Utility
• Search through the menus for Secure Boot
• Set Secure Boot to Disabled
• Saving my changes

After saving my changes and restarting my computer, it was working with the external monitors!