Thermistor failure

Hello Reprappers,

I am an absolute newcomer in the 3D printing. After building my Prusa i3 from a kit now I tried to start with "Pronterface" but I get the following message:

Error:0
[ERROR] Error:0

: Extruder switched off. MAXTEMP triggered !
Errorrinter stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
[ERROR] Errorrinter stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)

if I try with "Cura" there is the message: Opening serial port
Temperature: 454.

This also happens when I unplug the thermistors. So what can I do to get the machine working.

Thank you for advice. exobaer.

You could have a break in a wire or a loose connection.

Well now I tested the resistance at 32 degree C it is 74,5 kOhm. That mean the thermistors should be OK. So what could it else be?

it's either the wiring, or you have it plugged into the wrong connector.