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I am trying to change the keyboard backlight level to 100% at startup and there are many answers here on AU and none of them have worked for me. The answer that comes closest is trying change the value in /brightness but I am having some problems editing the file. Does anyone have a solution to this?

As a regular user I came upon this link:
~/sys/class/backlight$ ll
intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/

I changed to root (sudo -i) and followed the breadcrumbs to this directory:

root@qrp-N141CU:/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight# ll
total 0
drw-rw-rw- 3 root root 0 Mar 20 19:05 ./
drwxr-xr-x 6 root root 0 Mar 20 18:50 ../
-rw-rw-rw- 1 root root 4096 Mar 20 19:16 actual_brightness
-rw-r--r-- 1 root root 4096 Mar 20 19:01 bl_power
-rw-rw-rw- 1 root root 4096 Mar 20 20:24 brightness
lrwxrwxrwx 1 root root 0 Mar 20 19:01 device -> ../../card0-eDP-1/
-r--r--r-- 1 root root 4096 Mar 20 18:50 max_brightness
drwxr-xr-x 2 root root 0 Mar 20 19:01 power/
-r--r--r-- 1 root root 4096 Mar 20 19:01 scale
lrwxrwxrwx 1 root root 0 Mar 20 18:50 subsystem -> ../../../../../../../class/backlight/
-r--r--r-- 1 root root 4096 Mar 20 18:50 type
-rw-r--r-- 1 root root 4096 Mar 20 18:50 uevent

I have bolded above the four files I am interested in:
actual_brightness
bl_power
brightness
max_brightness

Somehow I changed the r/w values to 666 of /actual_brightness and /brightness. Examining /max_brightness revealed the value 60000, /brightness was set to 39210. In /brightness I tried to add the line 60000 but vim kept giving me errors about not being able to change the file. Since I don't know what I'm doing as root I backed out before I did any damage. (I know enough to really screw up things.)

FWIW, here's my setup:

OS: Ubuntu 20.10 x86_64
Kernel: Linux 5.8.0-45-generic
Shell: /bin/bash 5.0.17
DE: GNOME 3.38.2
CPU: Intel i7-10510U (8) @ 4.900GHz [45.0°C]
GPU: Intel UHD Graphics
Memory: 2.95GiB / 15.33GiB (19%)
Terminal: gnome-terminal
Resolution: 1920x1080 @ 59.93Hz
Host: N141CU [Clevo laptop]
Uptime: 2h 9m
Packages: 2505 (dpkg), 9 (snap)
WM: Mutter
WM Theme: Adwaita
Theme: Yaru-dark
Icons: ubuntu-mono-dark

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