HDMI in Manjaro

Good day to all!
This is not the first time I have created a topic with a problem with HDMI in Manjaro.

It seems I found the reason and at least some bad solution to the problem with HDMI.

Initial data:
PC with HDMI and DVI. TV with HDMI.
Accordingly, the TV is connected to the PC via HDMI cable.
TV, PC, cable, HDMI and DVI connectors - everything works fine on old versions of Manjaro.

To check, I installed MX Linux, Bodhi Linux, everything works correctly.
But after updating Bodhi Linux, a similar problem with no signal arose.

When trying to install the latest version of Manjaro from Live USB, a problem occurs.
Black screen, message “No signal”.

I connected the TV to the PC’s DVI via an HDMI-DVI adapter. There is a signal, the installation was successful.

But I can’t fully use the system, since the sound is not transmitted via DVI.

Try the following experiment:
Without turning off the PC, I connect the HDMI cable to the HDMI in the PC. There is a picture, everything works.
I reboot the PC (TV remains connected via HDMI), there is a picture, everything works.

I turn off the TV and PC. I disconnect from the 220V power supply.
I turn on the TV and PC (TV remains connected via HDMI), there is no signal.

Without turning off the PC, I connect the HDMI cable to the HDMI in the PC. There is a picture, everything works.

What I noticed
The TV supports a resolution of:

  • 2060p * ​​30 frames and
  • 1080p * 60 frames
    And if in the system settings (when connected to the HDMI port of the PC) you select
  • 2060p * ​​30 frames - there is a picture.
  • 1080p * 60 frames - no signal.

It seems that after disconnecting the 220V power supply, each time you turn on the TV and PC, Manjaro selects 1080p * 60 frames.
Despite the fact that the PC turned off each time with the setting 1080p * 30 or 1080p * 24 frames.

Installed xorg-xrandr.

pacman -S xorg-xrandr

I tried changing the settings with the command. It worked successfully.

xrandr --output HDMI-A-0 --mode 1920x1080 --rate 24

I want to configure the command execution at system startup.
To check my guess, does the system really choose 1080p *60 frames every time it is turned on, which is why there is no signal on the TV.

xrandr --output HDMI-A-0 --mode 1920x1080 --rate 24

/etc/systemd/system/myhdmi.service; enabled; preset: disabled)
Active: failed (Result: exit-code) since Fri 2024-10-18 20:51:42 +07;

Process: 431 ExecStart=/home/userpc/app/hdmi.sh (code=exited, status=1/FAILURE) `
Main PID: 431 (code=exited, status=1/FAILURE)

`окт 18 20:51:42 blackpc hdmi.sh[518]: Can't open display`

But in the configured service an error occurs.
Please tell me how to change the screen frequency automatically when the system starts.

Operating System: Manjaro Linux 
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.7.2
Kernel Version: 6.10.13-3-MANJARO (64-bit)
Graphics Platform: X11
Processors: 2 × AMD A6-9500E RADEON R5, 6 COMPUTE CORES 2C+4G
Memory: 15.1 ГиБ of RAM
Graphics Processor: AMD Radeon R5 Graphics
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: A320M-H

You could try this kernel parameter:

video=HDMI-A-0:1920x1080@24

See: https://www.kernel.org/doc/Documentation/fb/modedb.rst