I get emails from readers every now and then — but no topic has caused more interest than the 6-pin fan header on my two Inter-Tech server cases, 4U-4416 and 4U-4129-N.

Perhaps for good reason, it allows for the internal 120 mm fans to be PWM controlled. But is completely undocumented! Let’s have a closer look 😃

Late 2018 I finally pulled the trigger and bought a Unifi 16XG 10GbE switch, I’ve wanted one for a long time. When I plugged it in for the first time, I realized it was pretty loud… It was the loudest thing in my rack — bummer.

Reads temperature and controls a fan using a PWM output, fan and alarm set point can be adjusted and is shown on a LCD. Uses an AVR ATmega8 microcontroller.