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Sent nozzle temp to 300C
Posted: Fri Jul 03, 2015 12:19 pm
by Airvent
Somehow I accidentally let the extruder temperature to reach about 300C. Firstly, I have no idea how this happened as I had set the target temperature to 190C as instructed (during calibration). Now the temperature won't stop rising. So, two questions....
Is the PEEK insulator definitely damaged?
What would cause the temperature to keep climbing when I have it set to 190C?
Thanks
Re: Sent nozzle temp to 300C
Posted: Fri Jul 03, 2015 2:13 pm
by teoman
It may not be damaged depending on how long it was heated.
It may be an electronics problem where a switch (mosfett) is stuck.
Or your pid has gone wonky. You could try to recalibrate.
Does it immediately start to heat up the moment you give power to the printer?
The other option is, your thermistor is going crazy and it was not at 300 degs.
Re: Sent nozzle temp to 300C
Posted: Fri Jul 03, 2015 2:45 pm
by Airvent
teoman wrote:It may not be damaged depending on how long it was heated.
It may be an electronics problem where a switch (mosfett) is stuck.
Or your pid has gone wonky. You could try to recalibrate.
Does it immediately start to heat up the moment you give power to the printer?
The other option is, your thermistor is going crazy and it was not at 300 degs.
I will try recalibrating it. UPDATE: I tried recalibrating it and it started smoking. Wiring problem?
It only begins to heat up when I give it a target temperature.
How would I fix a stuck mosfet?
It's odd because now when I'm heating it up, the reading stays between 14C and 16C but it's obviously heating up. I checked the wiring and it looks fine.
Thank you.
Re: Sent nozzle temp to 300C
Posted: Fri Jul 03, 2015 4:31 pm
by Polygonhell
The temperature on the LCD is what's being reported to the firmware, if it doesn't go up, the firmware will assume it needs to increase the power to the hotend to make that happen.
You don't have a s tuck MOSFET, that would cause the hotend to start heating as soon as power was applied and the thermistor would read the correct temperature.
You most likely have either a short with the metal part of the hotend or another wiring issue with the thermistor. It's possible the thermistor port on the Rambo is damaged, but the issue is most likely wiring.
Re: Sent nozzle temp to 300C
Posted: Fri Jul 03, 2015 5:38 pm
by BenTheRighteous
Is the thermistor still firmly seated in the hotend?