1

hi,

I’m using RAMPS 1.4.

When I open repetier host, my heatbed temperature shows approximately 29 degrees Celsius, but my extruder temperature says that it’s 0 degrees, which is not possible. I checked all my wiring and nothing seems to be wrong. So I’m guessing it’s a problem with the firmware. If it is, can someone tell me what I’m doing wrong here? I’m using Marlin firmware.

Thanks a lot, Mitch.

2

You can disconnect the wire from the ramps board and use a meter to measure the resistance. Should be around 100k for most typical printers. If its reading open than either its the wire or the thermistor thats gone bad. If its reading properly, it is probably something in the Marlin configuration file, it might be the board is set to the incorrect type or the sensor is set wrong. For a ramps board under the temp sensor section it should look something like this

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_3 0
#define TEMP_SENSOR_BED 1

3

If you’re sure the wiring is correct then you might have the wrong pin assigned in the firmware. Having the wrong sensor settings usually results in crazy readings but not zero, so I doubt that is it. It’s either looking at the wrong pin or the sensor/wiring/pin is faulty. I would swap plugs on the bed & extruder sensors and see if you still get zero. That should help narrow it down.

-Jesse