Hello everyone,
My problem might seem straightforward for some of you, but I still would like to have some advice.
My printer has two extrusion heads and one heated bed.
Some time ago, the regulation of the bed temperature stopped working. The bed's thermistor information did not reach the PCB, which assumed that the temperature was always 70°C even when heating of the bed had been triggered.
As a result:
- when the forced temperature was below 70°C, the heating did not start
- when the forced temperature was above 70°C, the heating never stopped, leading to temperatures beyond 90°C
I checked that indeed the bed was overheating with a temperature IR sensor.
Subsequently, each time I started the heating of the bed with T>70°C, the fuse blew up. However, one time not only the fuse blew up, but the power supply board was harmed (even if max current was 16A).
After replacing the board, I started to investigate what was the issue, and I found that the pins on the main control board (AZTEEG X3, from Panucatt Devices) associated to the bed's thermistor were shortcircuited.
I have replaced the thermistor today, thinking it was the one who failed. But it appears that the new thermistor did not change anything. I still read few tens of ohms accross the two pins (and not the 100k Ohms specified for the component).
Moreover, now the heating does not work for neither the bed or the two extrusion heads. I now read for the extrusion heads' thermistors a value of 4 k Ohms accross the board's pins (against the supposed 100k Ohms).
Do you have any advice for me to continue troubleshooting? Or about where I should start looking for a shortcircuit?
Maybe the control board failed after the repeated episodes of current overshoot, due to unregulated heating?
Thank you a lot for your feedbacks.
