TAZ3

Current problem: we think the thermal resistor (heater) in the extruder is broken.

Reproduce:

* Start preheating
* *Head does not become hot*
* After some time "ERR: temp min" displayed on the LCD

What works:

* Thermistor (temperature sensor): Head temperature is measured correctly and displayed on the LCD
* PSU and mosfet: LED02 flashing on the RAMBO board during preheating
* Cables: the pair of red cables have ~12V on them during preheating