Cobra Forum

Linux => Installation & Upgrades => Topic started by: kalpana on Oct 10, 2023, 05:11 AM

Title: Software Update last week of 22.04 and 23.04, now can't detect external monitor
Post by: kalpana on Oct 10, 2023, 05:11 AM
I have two laptops:

pyxis runs 22.04LTS on a Lenovo X1E with a Nvidia GTX 1050 Ti and one external monitor connected via HDMI
crux runs 23.04 on a Lenovo Legion Pro 7 with a NVidia RTX 4080 with two external monitors: a 4K BenQ monitor via USB-C to DisplayPort, and a Dell HD monitor connected via HDMI

I've been running both of these machines for months, just updating (i.e., not upgrading) the software weekly. All external displays worked fine.

I run Software Updater on Fridays. After last week's update (6/30), the external monitors disappeared - they're not detected at all

I'll focus on the Legion Pro machine, crux, because that's my main machine.

I know that the hardware is connected properly since I can run Windows 11 and can use all three screens (the laptop and two external monitors).

I have these drivers installed:

$ ubuntu-drivers devices
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
modalias : pci:v000010DEd000027E0sv000017AAsd00003B64bc03sc00 i00
vendor : NVIDIA Corporation
model : GN21-X9
driver : nvidia-driver-535 - distro non-free recommended
driver : nvidia-driver-525-open - distro non-free
driver : nvidia-driver-525 - distro non-free <- using this one
driver : nvidia-driver-535-open - distro non-free
driver : nvidia-driver-525-server - distro non-free
driver : xserver-xorg-video-nouveau - distro free builtin

Control Center/Displays shows only the laptop screen. No external displays are shown. Why are they not detected?

Software & Updates aka software-properties-gtk says that I'm using NVIDIA driver metapackage from nvidia-driver-525 (proprietary).

Questions:



Any suggestions? Thanks!