Extruder Temperature Out of Control

Hello everyone,

I'm running a Hictop Prusa i3. I have ran it rather successfully the last 4 months or so. I had fixed a clogged nozzle, and on my next print I believe my extruder heater cables shorted out and melted one of the connections off. I resoldered the connected and booted, but temperature ramps to about 210 immediately and I can't get it to cool. I'm thinking something has blown. Any suggestions?

RFlyer

It sounds to me as though you have shorted or damaged the extruder thermistor.

If it is heating up as soon as power is switched on, it's most likely the mosfet gone short circuit

Quote
obewan
If it is heating up as soon as power is switched on, it's most likely the mosfet gone short circuit

I thought this might be the case. I believe i have read that the heater could be powered on the E1 supply rather than E0 - do you know how this is done or if there is a guide?

If your useing marlin firmware you need to change the pin asignment in pins_RAMPS.h

Quote

/**
* Hi Voltage PWM Pin Assignments
*/

#ifndef MOSFET_D_PIN
#define MOSFET_D_PIN -1
#endif
#ifndef RAMPS_D8_PIN
#define RAMPS_D8_PIN 8
#endif
#ifndef RAMPS_D9_PIN
#define RAMPS_D9_PIN 9
#endif
#ifndef RAMPS_D10_PIN
#define RAMPS_D10_PIN 10
#endif

swap the 8 and 9