Blackscreen issues on Lenovo Yoga C940

Hi,

I’m trying out Linux for the first time in a few years (I’ve used Mint for a bit like 12 years ago, trying to breathe some new life into an old pc before I could buy a new one). This time on my Lenovo C940 laptop, but it’s not going smoothly at all. The issue I’m having is a blackscreen issue, either on startup, after login, or after the laptop goes to sleep (by either going to sleep automatically, by closing the laptop, or systemctl suspend).

I’ve tried a few different distro’s, to name a few: KDE Neon, Fedora KDE, Zorin, CachyOS with KDE. But also some GNOME based ones. When using KDE with Wayland, the blackscreen happens either at startup or after login. With X11, Wayland using graphic safe mode / nomodeset and GNOME it starts perfectly fine, but after sleep / suspend it goes to blackscreen. The blackscreen is a pure black screen, without the option to press ctrl+alt F2 (or F5 for me) as I’ve been seeing online. The only way to get out of the blackscreen is by pressing the power button for a few seconds. Currently I’ve got KDE neon installed.

I’ve tried some fixes, based on some youtube vids, online forum finds, and some fixes suggested by ChatGPT. These include stuff like adding i915.enable_psr/fbc/dc=0, i915.forceprobe=* to startup / grub, checking some mem_sleep options.

Some laptop info:

  • Lenovo Yoga C940, 14” 2-in-1 laptop
  • Intel Iris Plus Graphics G7 (rev 07)
  • Touchscreen works fine, touchpen works fine, fingerprint doesn’t work, but I’m seeing a lot of issues online about the fingerprint sensor of this laptop with linux. Probably fixable, but hasn’t been my main focus yet.

If anyone knows some fixes to try that would be amazing, I really want to give linux another go. I’ve tried giving as much info as possible, but if more info is needed please let me know.

Given that you are having trouble in general, not specifically one distro or another, suggests the issue is hardware related. Have you installed the latest BIOS firmware for that laptop? Assuming your Laptop is a C940IIL the most recent bios is from 2023. If not an IIL then I recommend you go to Lenovo’s support website and check with your serial number. It seems you can only install the BIOS from Windows, but there may be a Linux workaround using the “Firmware” app.

for using a windows installer, i can recommend this utility for booting to live version of windows in order to run the .exe on a one time basis.