Filament Jam

After having the leveling fail by pushing too hard on the leveling plates I had a filament Jam. This is eSun PLA which I switched to after lots of successful prints with HIPS. After reading some of the threads here with similar problems I got an infrared thermometer and checked the head temperature. I set it to 205C and monitored the temp at the copper colored extruder head and when the temp got to 205 my thermometer read only 50 degrees C. It did go steadily up from 21 to 50 degrees as the indicator rose but stopped at 50 while the software read 205. I did the same thing setting the bed to 60 degrees and measured it with the same thermometer and it showed 70 on the thermometer when the software showed 60 - I figure that is close enough to call the thermometer reasonably accurate.

So I believe the reason I can’t pull the filament out of the extruder (having opened the latching mechanism) is that the head is not heating up properly. What things should I check and in what order to further troubleshoot the problem.

The thermistor is probably failed. you will need a replacement. if you are under warranty call lulzbot support for a new one. If you are out of warranty, get one here: http://i-t-w.com/parts/thermistor-for-hexagon-100k