[PROBLEM] R-Pi 4B 4G - PoE - Fan issue

[Tim Curtis]

Here's from the README in /boot/overlays/

Code:

Name:   rpi-poe
Info:   Raspberry Pi PoE HAT fan
Load:   dtoverlay=rpi-poe,<param>[=<val>]
Params: poe_fan_temp0           Temperature (in millicelcius) at which the fan
                               turns on (default 40000)
       poe_fan_temp0_hyst      Temperature delta (in millicelcius) at which
                               the fan turns off (default 2000)
       poe_fan_temp1           Temperature (in millicelcius) at which the fan
                               speeds up (default 45000)
       poe_fan_temp1_hyst      Temperature delta (in millicelcius) at which
                               the fan slows down (default 2000)
       poe_fan_temp2           Temperature (in millicelcius) at which the fan
                               speeds up (default 50000)
       poe_fan_temp2_hyst      Temperature delta (in millicelcius) at which
                               the fan slows down (default 2000)
       poe_fan_temp3           Temperature (in millicelcius) at which the fan
                               speeds up (default 55000)
       poe_fan_temp3_hyst      Temperature delta (in millicelcius) at which
                               the fan slows down (default 5000)

Here's from a blog post 
https://jjj.blog/2020/02/raspberry-pi-po...n-control/

Code:

# PoE Hat Fan Speeds
dtparam=poe_fan_temp0=65000,poe_fan_temp0_hyst=5000
dtparam=poe_fan_temp1=67000,poe_fan_temp1_hyst=2000

Then, reboot! Now, the fans won’t kick on until they hit 65’C, they’ll speed up at 67’C. For my setup, that silences them almost completely, while still keeping them reasonably cool and safe.