Odd issue - Bed Temp, Nozzle Temp and extruder all stop during the print

Simulanon

Hi all,
I am having the oddest issue trying to print a large print today (print takes up vast majority of the bed print volume)

When printing the first layer (furthest i have gotten so far) i started noticing that the temps were resetting to zero while the printer was going and the extruder motor would stop. This would happen nearly every time, in a similar spot each time the head was going around and doing the brim. 

I finally caught it happening on the third printing attempt, on the screen, all the temps flash and reset to zero, then the temp probes kick in and show the current temp again, but with a heat setting of zero.
I was able to quickly hit the more option on the screen, then heat and set the heat back to the right temp and the print would just keep going. Then it would reset as it went around again and i had to set the temp on the screen again. Did this for a few rounds and decided to check out my gcode.

I use the newest version of Cura and the newest offical firmware from JGAurora.
The code was great, no commands resetting the heat or anything like that.

I re-sliced the file several times but it kept happening, so its not a slicer issue. The print i had it do directly previous to this one worked flawlessly. It is just something about this print. Im not sure if i am triggering some safety mechanism due to being pretty close to the edge of the build volume or what. Although i would think it would stop the print completely, not just shut off the heaters and stop the extruder motor.

Currently i have sat here for a couple hours babying the print and setting the heat back on every reset. Once it got past the wall it seems to be printing the rest of the bottom layer pretty well. No resets yet.

Will update as the print progresses, but i wanted to see if anyone has encountered this before.

Many thanks!
Jim

Simulanon

Just had another reset on the first layer, this one was nowhere near the edge of the build volume, there goes that theory...
Still printing. I have made sure all cable connections are tight into their respective ports.

Simulanon

Missed this reset by a minute or so. This shows the lines as the nozzle heats backup and the extruder kicks back in.

Samuel Pinches

Perhaps upload your gcode file here for us to look at. Also consider trying the print via USB cable vs SD card.

Simulanon

I have tried both printing via SD and USB. I think i may have figured it out. While i was changing the temp back from zero on one of the resets, i caught a 'Sensor error' flash across the temp indicator.
That led me to play with both the thermistor wire connection and the bed heating connection. Bed connection seemed rock solid, but when i went to touch the thermistor connector i was able to get it to do multiple resets in a row when moving that coupling around. I have secured the coupling and it appears to be working as normal again (at least for the past hour)

So odd! I guess if there is a sensor failure on the thermistor, then the heat for both hot end and bed reset to zero, and because there isnt code in the gcode to constantly reset the temp (obviously) back to printing temp it would just continue the print without heated bed, hot end or extruder.  I do kinda wish that if there is a sensor error, then the whole print pauses, but i guess that could be a mess too.
My suspicion is the extruder stopped when the heat hit a certain low temp to prevent the filament from being torn to shreds by the extruder gear.