# Hotend drops to 175 ºC once extrusion starts (MINTEMP error reported)

Hotend drops from 205 °C to 175 °C, and then the printer errors MINTEMP. How can I fix this? Fan is not starting yet.

#define  DEFAULT_Kp 28.65
#define  DEFAULT_Ki 2.80
#define  DEFAULT_Kd 73.33

#define HEATER_0_MINTEMP 5


MINTEMP is 5 °C? It's impossible it's getting that cold.

• Is your fan coming on? Do you have an M106 in your gcode?
– Davo
Sep 9 '19 at 19:45
• Your hotend thermistor is reporting -27 ºC considering the bed of 27 ºC (so your ambient is about 27 ºC) there must be something seriously wrong, possibly the thermistor.
– 0scar
Sep 10 '19 at 6:43
• @0scar the dropping spikes tell the story of disconnecting the sensor... Sep 10 '19 at 9:00
• @Trish Excatly, something seriously wrong. You see the ambient temperature being (very shortly) reported correctly at about -10 minutes in the graph, so this must be a connection issue or faulty sensor.
– 0scar
Sep 10 '19 at 9:36
• Yes this is a connection issue, some wire can be loose or internally broken. If the sensed temp is negative the thermistor is damaged or a broken end terminal. This error is normal when your wires are not well routed and protected or too tight. Sep 10 '19 at 18:16