Heatsink fan stopping in midprint
Hi,
Some background info before going to the issue. When first time powering up the printer (kit) I got MINTEMP-error from the hotend. I checked the wiring (reconnected) and everything seemed to be fine. I switched the heatbed and hotend termistor wirings and confirmed that the issue is not in the Rambo-board (error switched to heatbed temp). After switching the wirings back the error went away and it didn’t appear to me anymore.
Few days ago I got my spare heatbed from Prusa and I installed it without any problems. Prints were turning out fine and everything seemed to be normal. But now to the real issue. I have had now three times a situation where the heatsink fan has stopped from running in midprint. The LCD doesn’t give any error, it just shows temperature indication of 21/205° for the hotend. The printer has continued printing normally like nothing happened. I have pressed the X-button below the menu rotary to stop the print. Printer has resetted itself but the temperature reading has been the same 21 degrees. After a few seconds (time has varied on these three times) the fan has started rotating and the temperature reading has been correct again.
I setted the hotend temperature for around 60 degrees to get the fan on and tried to get the error state repeated by touching and moving the spiral wrap of extruder and the wirings inside the Rambo-cover without result.
So considering the first time MINTEMP-error and the fact that the faulty temperature reading hasn’t changed by resetting the printer it seems to me that the hotend thermistor wiring is faulty. But I’m still wondering why does not the printer give any error message. Should the temperature drop down to the 15 degrees (like in MINTEMP-error) if the thermistor connecton is losted during print? Or is the wiring partly “broken” and that’s why the temp is in 21 degrees in the fault state?
What do you pros suggest that I should do with this? Can I order a new wiring from the connector to the Rambo-board? Should I make a new wire myself for the connection? I would also be ready to order the hole new thermistor with all the wiring. This kind of problem is one of those that I don’t want to encounter while printing as the PTFE-tube etc. could melt when the fan stops during print.
Thanks already in advance for your replys.
Br,
Lintsi