M112 Called - Emergency Stop - Thermal Runaway Protection  

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Another example of this cooling fan ramping up and temps going nuts for a bit but then it seems to level out nicely.  Seems my thermistor is picking up the temps good then but something it causing those measurements to go wonky.  I am running a silicon sock.  Also installed a new fan shroud last night just in case any small warping would put air where it should not go.

prusa3d_fw_MK3S_3_9_1-RC1_3512.hex  OctoPrint 1.4.2 Python 3.7.3 OctoPi 0.17.0

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

I will try adding some thermal paste and see if it lowers this effect.  

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Replacement heater gets here today from Filastruder.

https://www.filastruder.com/collections/prusa-specific/products/prusa-specific-e3d-heater-for-mk3-mk3s-printers

I contacted Prusa support and sent this discussion URL and they recommended replacing the heater then checking all voltages related to the heater:

https://help.prusa3d.com/en/article/multimeter-usage_2117

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

I often order from Filastruder.  If you need it quicker in the future, Amazon can deliver theE3D V6 Prusa Heater with Prime.  

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Fixed.  New heater cartridge fixed this issue.  Only part replaced with this troubleshooting at this time.

Worked with Prusa support and this was their recommendation.

Replaced with this E3D cartridge from Filastruder:

https://www.filastruder.com/collections/prusa-specific/products/prusa-specific-e3d-heater-for-mk3-mk3s-printers

Fan turned on at around -12min.  There's a tiny ripple where the temperature PID had to adjust for the fan kicking on.

Threw me off that the erratic temperature swings were due to the cartridge.  Doesn't seem possible a heater block could drop 30C and go back up 30C in two seconds so I was thinking the temperature measurement was off but maybe the faulty heater cartridge would affect the temperature measurement circuit?

Stoked!  Prusa support was very responsive and helpful.  Good stuff.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Posted by: @charles-h13

I often order from Filastruder.  If you need it quicker in the future, Amazon can deliver theE3D V6 Prusa Heater with Prime.  

Thanks for this!

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

All was well for a few prints and now this is happening again...

- Voltages verified w/ support

- new e3d thermistor and heater block installed

- firmware updated to 3.9.1 from Prusa's official page

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Swapped out my .35A fan with this replacement:

https://www.ebay.com/itm/Prusa-i3-MK3-MK3S-Prusa-Bear-Zaribo-Fan-5015-Parts-Cooling-Fan/183786454185

So far, so good with a five hour print.  Can a bad fan do anything to feedback into the system to affect temperature measurements?  Grasping at straws here but I've got nothing else minus a possible faulty Rambo if I see errors now?

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Those jumps are best explained by a broken wire ... try starting up the printer cold, then firmly moving the extruder harness around while watching the thermal sensor monitor.  If you see the extruder temp flicker even once, you have a broken wire. 

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Posted by: @tim-m30

Those jumps are best explained by a broken wire ... try starting up the printer cold, then firmly moving the extruder harness around while watching the thermal sensor monitor.  If you see the extruder temp flicker even once, you have a broken wire. 

I'm on my 3rd new thermistor and 1st new heater cartridge.  Handled them gently when installing every time.  Wires should be solid currently.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Last night I completed a four hour print just fine.  No blips at all on the graph.  235F.

Today I fire up a print and get this.

Going to check the thermistor connection on the rambo.  Curious if that is loose in any way.

From my point of view, seems like the Rambo may be next to replace.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

One commonality with all this troubleshooting has been that the thermistor was replaced and that header on the Rambo plugged back in.  Seemed good for a few prints then would start having issues.

I disconnected the thermistor from the Rambol.  I removed the two pins from the plastic thermistor plug and pushed in the two contact tabs per wire so they would put more pressure on the Rambo pins to ensure a solid contact.  So far so good on this print.  

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

@jurassic73

Such abrupt temperature jumps almost always indicate a defective thermistor wire or a loose contact. I had this problem several times. The fault is difficult to detect, because a cable break inside the insulation is not visible to the naked eye.

A defective cartridge heater does not cause such extreme jumps but lets the temperature curve run smoother.

After pidtuning the temperature fluctuations should be in the range of +- 1-2 degrees C.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

@karl-herbert

Before someone snipes.  It could be the wiring also.  The wire to the molex is a part of the thermistor in my book.  

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Thanks for the replies.  As noted previously, I'm on my 4th thermistor.  The currently installed thermistor and heater cartridge only have maybe a dozen hours of printing time on them when I saw this again.  No way the wires broke in that time.  I'm very curious about the molex connector changes I made though for a more solid connection on that end.  I could certainly imagine a connector with a lighter/marginal pressure to pin contact being moved/vibrated when the printer is printing and causing faulty measurements.

If this turns out to be the fix, awesome... but at the same time it would be frustrating that the connector is not doing what's needed in it's role.  We'll see.  I have a few things to print and will report back.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

@jurassic73

I removed the Molex connectors, that they are a weak point and soldered the wires directly. Once I also had a cold solder joint on the Einsy board. I searched there for a while until I found the error. In any case I would search in the area of the thermistor, the wires and contacts. Should the thermistor break down, I will gladly accept repeated soldering. With my MK3 I have used only the 2nd thermistor for almost 3 years. Mostly the moving wires are defective.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

@jurassic73

Can you post an image of the thermistors you are using?  Where are you?

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

https://www.filastruder.com/collections/prusa-specific/products/prusa-specific-e3d-thermistor-cartridge

This exact part.

I'm on my second 3-4 hour print after squeezing the flaps in on the the individual molex pins in the plug for better contact.  Hoping this is the fix.  Karl's method to solder the pins passed through my mind but now hearing someone did it with good results will put it on my todo list if temps go wonky again.

RE: M112 Called - Emergency Stop - Thermal Runaway Protection

Did you solder that to the Einsy?