Extruder switched off. MINTEMP triggered ! Problem, pls help me .

[Yan Zhuang]

I connect my M2 with pronterface, and I got this problem 

Thank you.

Connecting...

start

Printer is now online.

echo:Marlin: 1.0.0 RC2 for MakerGear M2

echo: Last Updated: 2012-05-30 | Author: johnny

echo: Free Memory: 4775  PlannerBufferBytes: 1232

echo:Using Default settings:

echo:Steps per unit:

echo:  M92 X88.88 Y88.88 Z400.00 E471.50

echo:Maximum feedrates (mm/s):

echo:  M203 X500.00 Y500.00 Z250.00 E200000.00

echo:Maximum Acceleration (mm/s2):

echo:  M201 X9000 Y9000 Z30 E10000

echo:Acceleration: S=acceleration, T=retract acceleration

echo:  M204 S3000.00 T3000.00

echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum xY jerk (mm/s),  Z=maximum Z jerk (mm/s)

echo:  M205 S0.00 T0.00 B20000 X20.00 Z0.40 E5.00

echo:PID settings:

echo:   M301 P7.00 I0.10 D12.00

echo:SD card ok

Error:0

[ERROR] Error:0

: Extruder switched off. MINTEMP triggered !

Error:Printer stopped deu to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

[ERROR] Error:Printer stopped deu to errors. Fix the error and use M999 to restart!. (Temperature is reset. Set it before restarting)

[David Ras]

The RAMBO cannot see a voltage level from the thermistor.  Check the resistance with a voltmeter at the plug where it plugs into the RAMBO.

[Dale Reed]

Yan Zhuang,

I'm going to assume you are a new M2 user, trying it out for the first time.  If I am wrong on this assumption, please excuse this introductory information.

The bed and nozzle temperatures should read room temperature (typ. about 20 C) on powerup.  If either reads zero, you have an open circuit somewhere.  Check connections.

If you DO read room temperature on the nozzle OK, please note that If you are trying to run the extruder stepper (using the jog on the machine control panel of S3D, for example), you have to turn on the nozzle heat and wait until the nozzle temperature is above 170 C to run the extruder stepper.  The firmware prevents running the extruder stepper at lower temperatures to help keep you from getting a solid clog in the hot end or jamming or damaging something by jogging filament that can't possibly be melting.

If a temperature reading is zero, the corresponding thermistor circuit for measuring that temperature is open somewhere.  Each thermistor (one for the hot end, one for the bed) is a temperature-sensitive resistor.  Unlike most materials, it has a negative temperature coefficient -- that means the resistance goes down as the temperature goes up.  If you're handy with a multimeter, you can unplug the extruder thermistor from the RAMBo board, then measure the resistance.  IIRC, it's about 100 kOhms at room temperature.  I could be way off on that --- but it should not read zero ohms and it should not read open circuit!!!

I hope this is helpful.  Let us know what you find out.  (And please post on the Technical Support board at forum.makergear.com  ...)

Dale