ASUS ROG Screen Brightness Stuck at 100

After years on Windows, I finally switched over and everything [besides 1 issue] is working excellent!

My screen brightness is stuck at 100% and neither the slider in Battery and Brightness nor the FN keys work. Over the last few days l have tried everything in all related forum threads but nothing works. My ASUS BIOS doesn’t have an option to change from Dedicated graphics to Switchable, so thats the only option which I haven’t been able to try

Also, since l’m new to Linux, please can you give me step by step instructions.

Here’s my inxi -Fxxz` output:

System:
Kernel: 5.15.25-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.2.0
Desktop: KDE Plasma 5.24.2 tk: Qt 5.15.2 wm: kwin_x11 dm: SDDM
Distro: Manjaro Linux base: Arch Linux
Machine:
Type: Laptop System: ASUSTeK product: GL503VS v: 1.0
serial:
Mobo: ASUSTeK model: GL503VS v: 1.0 serial:
UEFI: American Megatrends v: GL503VS.308 date: 07/01/2020
Battery:
ID-1: BAT0 charge: 51.8 Wh (100.0%) condition: 51.8/62.6 Wh (82.8%)
volts: 15.2 min: 15.2 model: ASUSTeK ASUS Battery serial: N/A
status: Not charging
CPU:
Info: quad core model: Intel Core i7-7700HQ bits: 64 type: MT MCP
arch: Kaby Lake rev: 9 cache: L1: 256 KiB L2: 1024 KiB L3: 6 MiB
Speed (MHz): avg: 903 high: 918 min/max: 800/3800 cores: 1: 900 2: 900
3: 906 4: 918 5: 900 6: 900 7: 900 8: 900 bogomips: 44817
Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
Device-1: NVIDIA GP104BM [GeForce GTX 1070 Mobile] vendor: ASUSTeK
driver: nvidia v: 510.54 pcie: speed: 8 GT/s lanes: 16 bus-ID: 01:00.0
chip-ID: 10de:1be1
Display: x11 server: X Org v: 1.21.1.3 compositor: kwin_x11 driver: X:
loaded: nvidia gpu: nvidia display-ID: :0 screens: 1
Screen-1: 0 s-res: 1920x1080 s-dpi: 143
Monitor-1: DP-2 res: 1920x1080 dpi: 142 diag: 394mm (15.5")
OpenGL: renderer: NVIDIA GeForce GTX 1070/PCIe/SSE2
v: 4.6.0 NVIDIA 510.54 direct render: Yes
Audio:
Device-1: Intel CM238 HD Audio vendor: ASUSTeK driver: snd_hda_intel
v: kernel bus-ID: 00:1f.3 chip-ID: 8086:a171
Device-2: NVIDIA GP104 High Definition Audio vendor: ASUSTeK
driver: snd_hda_intel v: kernel pcie: speed: 8 GT/s lanes: 16
bus-ID: 01:00.1 chip-ID: 10de:10f0
Sound Server-1: ALSA v: k5.15.25-1-MANJARO running: yes
Sound Server-2: JACK v: 1.9.20 running: no
Sound Server-3: PulseAudio v: 15.0 running: yes
Sound Server-4: PipeWire v: 0.3.47 running: no
Network:
Device-1: Intel Wireless 8265 / 8275 driver: iwlwifi v: kernel pcie:
speed: 2.5 GT/s lanes: 1 bus-ID: 03:00.0 chip-ID: 8086:24fd
IF: wlp3s0 state: up mac:
Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet
vendor: ASUSTeK driver: r8169 v: kernel pcie: speed: 2.5 GT/s lanes: 1
port: d000 bus-ID: 04:00.0 chip-ID: 10ec:8168
IF: enp4s0 state: down mac:
IF-ID-1: nordlynx state: unknown speed: N/A duplex: N/A mac: N/A
Drives:
Local Storage: total: 1.14 TiB used: 47.12 GiB (4.0%)
ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLW256HEHP-00000
size: 238.47 GiB speed: 31.6 Gb/s lanes: 4 serial: temp: 43.9 C
ID-2: /dev/sda vendor: Seagate model: ST1000LX015-1U7172 size: 931.51 GiB
speed: 6.0 Gb/s serial:
Partition:
ID-1: / size: 116.24 GiB used: 11.15 GiB (9.6%) fs: ext4
dev: /dev/nvme0n1p6
ID-2: /boot/efi size: 96 MiB used: 25.3 MiB (26.3%) fs: vfat
dev: /dev/nvme0n1p1
Swap:
Alert: No swap data was found.
Sensors:
System Temperatures: cpu: 56.0 C pch: 56.5 C mobo: N/A gpu: nvidia
temp: 58 C
Fan Speeds (RPM): cpu: 2400
Info:
Processes: 233 Uptime: 14m Memory: 15.59 GiB used: 1.98 GiB (12.7%)
Init: systemd v: 250 Compilers: gcc: 11.2.0 clang: 13.0.1 Packages:
pacman: 1205 Shell: Zsh v: 5.8.1 running-in: konsole inxi: 3.3.13

Go to Laptop/ASUS - ArchWiki and see some pointer there.
For more detailed backlight issues, see here Backlight - ArchWiki

Hi there. Sorry if I’m too late but, did you manage to resolve the issue?
I’m on pop os and like you, tried all the things I could.