Hi @Andre,
as far as I know, the argon1.sh script tries to enable I2C, UART and gpio-ir automatically. Naturally this requires, that the distro you use is supported to work properly with that installation script.
For fan control, I2C is needed to send the control messages to the MCU at the pcb of the Argon One case. If I2C is enabled, it’ s possible to do it manually with messages like this (Argon one v3 power button and fan scripts issue - #14 by HarryH):
set fan speed to 100%
Argon One V2
i2cset -y 1 0x1a 0x64
Argon One V3
i2cset -y 1 0x1a 0x80 0x64
You can use the last value 0x64 to vary between 0x00 (fan off) and 0x64 (100) to control the fan speed. Other values above this trigger some other functions such as shutdown (0xff): documentation(little bit outdated)
Attention: If you use the i2cdump command, it happens that the MCU stucks and the behavior is like the thread starter @olzzalm reported, until you remove the power supply for some seconds.
If you has triggered the shutdown (held button for >=3 seconds and <5 seconds, or use the remote control power button) it could happens what the MCU is disconnected from I2C bus until you remove the power supply or hold the power button for >5 seconds to force power off.