I have been using Fedora Linux 41 and an external monitor connected using a USB-C cable and sometimes with two different USB-C hubs with an HDMI port. The monitor have been used like this on several machines, Intel, Apple M2 and now AMD.
Applied updates to Fedora 42 last week.
Disconnected the USB-C hub at some point on Monday, since then the machine have not detected the external monitor as a second display using either USB-C hub with HDMI cable or USB-C cable directly to monitor. When connected using a USB-C cable the machine will charge.
Thursday I made a clean install of Fedora 41, as this did not solve the problem I also applied the updates to Fedora 42.0
What can I do to fix this?
The machine is a
Lenovo Yoga Slim 7 ProX 14ARH7
AMD Ryzen™ 7 6800HS Creator Edition × 16
AMD Radeon™ Graphics
The machine only have USB ports, no HDMI port
Fedora Linux 42 (Workstation Edition)
Wayland
Gnome 48
Linux 6.14.6-300.fc42.x86_64
Sometimes it is necessary to disconnect the entire system from the power supply. This often happened with thunderbolt controllers in Thinkpads.
Some systems have an option in UEFI settings that can be used to disconnect the internal battery. Some systems have a small emergency-reset hole at the bottom. In either case disconnect the system from AC power and go to UEFI settings to disconnect the internal battery or shutdown the system and insert a straightened paper clip into the hole to cut off power supply temporarily.
Then connect AC power and turn on the system.
This could restore the full funcionality of the system / usb-c ports.
I disabled the battery in the bios as suggested and booted first from a live image of Fedora 40 to verify and the external display worked.
After that I booted back in to the installed system of Fedora 42 which was using kernel-6.14.9-300.fc42 and the display no longer worked.
I then installed kernel-6.14.1-300.fc42, disabled the battery once more and the external display is now working.