Arch Linux

RNVI

Member

Registered: 2026-03-29

Posts: 3

[SOLVED]Installed Arch can't use the external monitor

Hello! I am using a setup with laptop and external monitor connected via USB-C-to-HDMI connector. During the installation in liveUSB, both monitors worked perfectly - however, after installation only the laptop internal monitor is working - system doesn't 'see' external one at all

get-edid returns
'Looks like no busses have an EDID. Sorry!'
Specs:
AMD R7-5800U
AMD Radeon RX Vega 8
16GB DDR4

Last edited by RNVI (2026-03-29 16:42:57)

I0F

Member

Registered: 2022-02-01

Posts: 7

Re: [SOLVED]Installed Arch can't use the external monitor

What DE or WM are you using? Do both monitors show something while booting?

RNVI

Member

Registered: 2026-03-29

Posts: 3

Re: [SOLVED]Installed Arch can't use the external monitor

Hello. Problem persists both on clean arch before gui installation, hyprland, and KDE+Kwim
Monitors work in UEFI setup, different OC and arch linux live usb. During the boot of the installed system only the internal monitor shows the log
Moreover, previous installalation of arch on the same setup had both monitors working, problem appeared afrer clean reinstalling (with formating the disk)

Last edited by RNVI (2026-03-29 11:39:52)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 74,659

Re: [SOLVED]Installed Arch can't use the external monitor

for OUT in /sys/class/drm/card*; do echo $OUT; edid-decode $OUT/edid; echo "================="; done

You'll need https://archlinux.org/packages/extra/x86_64/v4l-utils/

connected via USB-C-to-HDMI connector

What exactly is that thing? Is the USB-C you're currently using the same you were using before and is it a hybrid w/ alternate DP mode?

During the boot of the installed system only the internal monitor shows the log

Please post your complete system journal for the boot:

sudo journalctl -b | curl -F 'file=@-' 0x0.st

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RNVI

Member

Registered: 2026-03-29

Posts: 3

Re: [SOLVED]Installed Arch can't use the external monitor

Problem solved - for some reason, half of the kernel drivers weren't working properly
Full reinstall from a different USB stick fixed the problem