hephaestus

Hello, My UMO Original (not +0) has developed an under extrusion problem. One possible culprit is the temperature sensor on the print head. I’ve been unable to find a clear answer online or in the documentation as to what type of sensor this is. Is it a K-type thermocouple? Is it a PT-100 thermocouple? Is it a thermistor? What values should I be looking for when testing it? Resistance across the yellow and red leads is 1.6 ohms, if it’s is a PT-100 then it’s definitely shot. The sensor end inside the metal sleeve at the end is loose and slides back and forth inside. This sensor goes to a small board on top of the print head that has a AD597 chip on it. any help would be appreciated, this printer has been down for a couple months now and I want to join in the printing of supplies for the pandemic. thanks