Good day, im new here, looking for answer on internet about my issue i found this and I have the same trouble, my temperature sensor reading dont get more than 395-400, im trying to get 420 using ad497 from e3d, the first time I thought was the simplify3D but then change to repetier and the same result, then i try with adafruit MAX31855 and with the demo from adafruit works great i can read more than 700 celsius, but I dont know how to wired and installed on marlin, or where to change to my own pins, or i dont know if is some kind of limit in marlin firmware, is there anyone has solved this?, can help me please.