Display HDMI 7-inch jRP7007, problems with armbian (1024x768)

[Guillermo seara]

I've had an OrangePi4 LTS with a 7-inch IPS LCD HDMI jRP7007 external display for three years.
Always used it with the stock OrangePi operating system: Debian Bullseye xfce (2022).
I had Home Assistant installed and used a desktop client to view cameras and control lights from the touchscreen. Always looked good, and the only problem I had was that Debian didn't have power options, so I couldn't turn off the display; I had to do it manually with a button.

The October Home Assistant update completely broke my H.A., it stopped running completely, and when I tried to reinstall it, it threw up errors due to broken dependencies.
I tried to repair them, but nothing worked.
I simply started looking for a newer version, since the current requirements for H.A. are at least Debian 12.

I decided to try Harmony 13 with the XFCE desktop.
Everything works great. I installed H.A., Plex, Samba, etc.
It took me three days straight to get my entire home automation system back up and running in H.A.
H.A.'s encrypted backups took me hours until I found where the key was stored.
It later turned out that the full backup wasn't much use since all the sensors had a different ID, and 90% of the things were broken, and the add-ons weren't even in the backup.

After a week of struggling, I managed to get everything 100% working.
Debian 13 can turn my screen off and back on by touching it with a finger. This is great for quickly interacting with H.A.

The screen looks terrible and there are no resolution modes.

By default, Debian boots at 1024x768@60Hz.
On the Orangepi OS, it runs perfectly at this resolution and everything looks great.
It also has another 16:9 resolution mode at 848x480@60Hz.

But in Armbian, I only have two modes:

1024x768@60
800x600@60

The first mode, which looks great on OrangePi OS, here has a shaky, blurry image. The second mode, 800x600, looks perfect, but it's too small.

The monitor displays signal information.
In Armbian, when it boots at 1024x768@60, it appears to be in a different resolution: 987x768@57Hz.

That's why it looks so bad. When running at 57Hz, the image shakes, and when rescaling, the screen loses all detail.

I followed many tutorials and none of them worked:

Use cvt to calculate different resolutions and xrandr to create them.
However, any resolution created results in an error when trying to use it.

sudo apt install xrandr

cvt 1024 600 60
# 1024x600 59.85 Hz (CVT) hsync: 37.35 kHz; pclk: 49.00 MHz
Modeline "1024x600_60.00"   49.00  1024 1064 1168 1312  600 603 613 624 -hsync +vsync

xrandr --newmode "1024x600_60.00"   49.00  1024 1064 1168 1312  600 603 613 624 -hsync +vsync
xrandr --addmode HDMI-1 "1024x600_60.00"
xrandr --output HDMI-1 --mode "1024x600_60.00"

Use CVT and GTF to calculate the resolutions. I've tried countless resolutions, and it always fails and reverts to the previous one.

I can't find a way to make the screen look the way it should.

Does anyone have any ideas on how to fix this?
I suspect this is a kernel-level issue.

Sorry, but I'm using Google Translate.

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v25.11 rolling for Orange Pi 4 LTS running Armbian Linux 6.12.53-current-rockchip64

 Packages:     Debian stable (trixie)
 Support:      for advanced users (rolling release)
 Containers:   addon_491eb00d_hamh, addon_core_duckdns, addon_core_mosquitto, hassio_multicast, hassio_audio, hassio_dns, hassio_cli, homeassistant, hassio_observer, hassio_supervisor

 Performance:

 Load:         2%                Uptime:       15:06            
 Memory usage: 56% of 2.90G      Zram usage:   7% of 1.45G
 CPU temp:     38°C              Usage of /:   23% of 57G
 RX today:     184 MiB
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