A few months later, I tried to start up my Prusa Mini printer to print something for my daughter. But what I witnessed!
“Mintemp error: print head #12208”
According to the official documentation, this is a wiring problem, either with the heater or the thermistor cables.
However, the solution was very simple. Since I had moved my printer to the garage, where it is currently about 7°C, the print head was simply underheated, causing the printer to think that there was an error.
The quick solution was to turn on the direct heater and point it towards the printer enclosure. After a few minutes, once the temperature of the head had risen to 15°C, I was ready to start preheating both the head and the bed.
Warning! Do not leave the heater unattended! Keep an eye on the temperature of the printer parts to avoid overheating or damage. A few minutes will usually suffice to raise the temperature enough to clear the error.