ASUS Zenbook UM3402YAR

Hardware	PCI/USB ID	Working?
Touchpad		Yes
Keyboard		Yes
GPU	`1002:15e7`	Yes
Webcam	`3277:0010`	Yes
Audio (HDMI)	`1002:1637`	Yes
Audio (Speakers)	`1022:15e3`	Yes
Bluetooth	`1002:15e7`	Yes
Wi-Fi	`13d3:3568`	Yes
Fingerprint	`1c7a:0587`	Yes
TPM	`1002:15e7`	Yes

Installation

Install per the Installation guide. The default Arch installer does not support Secure Boot so you will have to disable it before performing the installation. If you want to dual boot with Windows you will need to configure UEFI Shim or similar to allow Secure Boot to be re-enabled and Windows to boot without additional steps to unlock Bitlocker drive encryption.

Accessibility

The ASUS firmware is accessed via F2 at boot. It is a graphical interface that can be navigated by mouse or keyboard. It is graphical and not text based.

Function keys

Key	Visible?¹	Marked?²	Effect
`Fn+Esc`	No	Yes	Enables Fn lock
`Fn+F1`	Yes	Yes	`XF86AudioMute`
`Fn+F2`	Yes	Yes	`XF86AudioLowerVolume`
`Fn+F3`	Yes	Yes	`XF86AudioRaiseVolume`
`Fn+F4`	Yes	Yes	`XF86MonBrightnessDown`
`Fn+F5`	Yes	Yes	`XF86MonBrightnessUp`
`Fn+F6`	Yes	Yes	`XF86TouchpadToggle`
`Fn+F7`	No	Yes	Keyboard backlight cycle
`Fn+F8`	No	Yes	Monitor select
`Fn+F9`	Yes	Yes	`XF86AudioMicMute`
`Fn+F10`	No	Yes	`XF86WebCam`
`Fn+F11`	No	Yes	Screenshot
`Fn+F12`	Yes	Yes	`XF86Launch1`
`Fn+Del`	Yes	Yes	`Insert`
`Fn+Right_Ctrl`	Yes	Yes	`Menu`
`Fn+k`	Yes	No	`Scroll_Lock`
`Fn+b`	Yes	No	`Pause`
`Fn+Up`	Yes	No	`Prior`
`Fn+Down`	Yes	No	`Next`
`Fn+Left`	Yes	No	`Home`
`Fn+Right`	Yes	No	`End`

The key is visible to xev and similar tools
The physical key has a symbol on it, which describes its function

Audio

On kernels 6.8+ where audio works at boot, one speaker (typically the right channel) may go silent after suspend/resume. The CS35L41 amplifier firmware fails to reinitialize due to missing ACPI GPIO reset pin, leaving the amp bound but without firmware (FW EN: 0 in kernel log).

Symptoms:

One speaker goes silent after suspend, the other works fine
ALSA mixer shows balanced levels (issue is at kernel driver level)
Reboot temporarily fixes it
journalctl -b -k | grep cs35l41 shows Cannot Initialize Firmware. Error: -16 on the affected amp

Warning Do not attempt modprobe -r / modprobe while the issue is active — this kills both speakers and only a reboot recovers.

The workaround is to unload the CS35L41 modules before suspend (while the I2C bus is still clean) and reload them after resume. Create the following system-sleep hook:

/usr/lib/systemd/system-sleep/cs35l41-fix.sh

#!/bin/sh
case $1 in
  pre)
    modprobe -r snd_hda_scodec_cs35l41_i2c snd_hda_scodec_cs35l41_spi 2>/dev/null
    modprobe -r snd_hda_scodec_cs35l41 2>/dev/null
    ;;
  post)
    modprobe snd_hda_scodec_cs35l41_i2c 2>/dev/null
    ;;
esac

Make it executable

No PipeWire restart is needed — the CS35L41 modules have zero direct users even while audio is playing.

Numpad 2.0

See asus-numpad and follow the instructions. UM3402YAR's Numpad corresponds to M433IA layout.

Note Numpad's brightness level is not adjustable via the asus-numpad driver, but is toggle-able.

Install asus-numpad^AUR, configure it then enable/start the asus-numpad.service.

Fan control

The UM3402YA laptop series do not have kernel modules to control fan profiles. EC registers are the way to control the fan level, where it also affects CPU performance and thermal throttling prevention depending on which fan pre-configured profiles the end-user writes to the registry (ASUS AIPT).

Note Writing the hexadecimals to the registry will stay persistent even after a reboot/shutdown.

Each laptop model might have different registry and hexadecimal values. Therefore, the best way to know the fan registry and the values to the registry which represents the fan profiles, is by installing nbfc on a windows machine and using the monitor tool supplied, in a terminal with administrator permissions:

> ec-probe monitor

While monitoring the changes using ec-probe for the fan registry, have MyASUS open and change the fan profile within it until you see a pattern change for a certain registry, in the ec-probe terminal window and the values corresponding to it. Once you found the registry, take notes of the hexadecimal values for each fan profile selected via MyASUS.

To read a registry's value:

> ec-probe read 0x61

On a UM3402YAR laptop with the 0x61 registry related to the fan profile, and a 0x00 hexadecimal value for setting the standard profile, the following should be written to the found registry:

> ec-probe write 0x61 0x00

You can now boot to your Linux operating system, and safely write the hexadecimal values to the registry as desired using the nbfc's EC probing tool.

Note If you are using NBFC-Linux instead of the original NBFC (C#/Mono), the EC probing executable is named ec_probe (with an underscore), not ec-probe (with a hyphen). Make sure to use ec_probe when running the EC probing commands on Linux.

The following were the fan profile hexadecimals for the 0x61 registry on a UM3402YAR laptop:

Fan Profile	Hexadecimal
Silent Mode	`0x01`
Standard Mode	`0x00`
Performance Mode	`0x02`