Ok, Lets dig in.
There are two kinds of of thermistors, NTC (negative temperature coefficient) and PTC (positive temperature coefficient). In general, you will see NTC sensors used for temperature measurement.
You can use an ohm meter to see if the value changes as the head heats up. The head wont heat up if the thermistor says is hot due to an incorrect resistive or firmware value.
Simple test is to pull the therm out completely, hook it to an ohm meter and put a lighter flame near it. The meter should change. if there is change you have a possible firmware problem.
Another way is to leave the therm electric plug in and pull the actual therm from the hot head. With your software running apply a flame. The software should respond.
Turn on code monitoring in Pronterface too.
Debugging
Isolation in testing is always the key.
I had the luxury of a dual head setup so I just swapped parts.
And depending on your hot end I had wires shorting against the heater block. I used the Kapston tape to isolate.
Hope this helps.
Edited 6 time(s). Last edit at 12/29/2015 03:01PM by Giantkiller.
