Ultimaker 2 "error temp sensor"

[fatalerror3141 0]

This is brand new out of the box, so it's in the middle of the set up and I can't access any menus yet.

Just after nozzle heating and loading the filament my printer says "error temp sensor". It cannot be canceled for fire reasons I guess.

I have removed the cover over the controller and tested the thermistor in the head and I get 108 ohms cold and it rises when it's hot. Is this normal behaviour?

Another thing I noticed after re-powering the printer with the cover off is the controller board gets very hot, i measured it with my ir gun at 80*c around where the stepper driver chips are. Surely this can't be normal?

[illuminarti 18]

Check that all of the wires and connectors in the mesh above the print head are correctly assembled, and also check that the wires are properly connected at the electronics board. Most likely the issue is that the the temperature signal isn't making it all the way back to the electronics board.

 

[fatalerror3141 0]

I measured the resistance on the back of the PCB Unpluged and pluged in I get 108 ohms.

I tried starting the printer up with the thermistor removed and the error comes up right away before all the bed levelling. It is "seeing" the thermistor.

 

[illuminarti 18]

Have you checked that the wiring looks good at the print head end? Since a loose or poorly assembled connection could cause intermittent issues. Also, check the wiring to the heated bed, as its possible that that's what its complaining about, not the nozzle.

 

[simon 1]

I had that with mine when I first had it. There was a bad connection on the heated bed. The thermocouple solder connection looked ok to the naked eye and in fact worked normally upto about 70 C but above that the connection broke down and became unstable. Re soldering the joint fixed the problem. I think there have been a few like that. It will probably test ok when it's cold, so check the connection with a magnifying glass.

[fatalerror3141 0]

Ok, I pulled back the mesh covering and everything looks secure, I removed and re-inserted all the connectors to be sure. The thermistor is attached to one continuous shielded cable until the PCB plug.

As for the bed, It did not go far enough into the set up to begin heating it, it was In the middle of heating for filament insertion I get the error. I did measure the thermistor in the bed ( at the PCB) . 108 ohms.

 

[illuminarti 18]

Did the problem happen after the filament insertion phase, or during it? Does the print head actually heat up? It could be that the heater isn't working, so that the firmware assumes a temp sensor problem when it doesn't see the nozzle heating up.

What is the ambient temperature where the printer is. Some people have had issues if its very cold, or very hot due to the built in safety limits.

 

[illuminarti 18]

Looking at the source code, 'Error Stopped - Temp Sensor' indicates that the temp sensor on the head is reading out of range - either too high, or too low.

 

[fatalerror3141 0]

The Print head most certainly heats up to a temperature that will melt the filament and I had the filament all the way in.

During the step where you have to press the button to confirm it is extruding I get the error message. Heating stops after the message.

Amb temp is approx. 18*c

 

[simon 1]

If your temp sensor is below 5 C you'll get that error. Try warming it for a few seconds with a hair dryer just to make sure it's above 5 degrees.

[simon 1]

Actually you get the addition of 'contact ultimaker support' if it's below 5C, so it probably isn't that.

[fatalerror3141 0]

Wow, your from Leamington. Im Only in Warwick!

It does have "contact Ultimaker support" at the bottom of the error message. Should i just see what they say?

It was more than 5*c in the room, The printer head was hot when i touched it but it cools after the error message.

 

[gr5 2,172]

Should i just see what they say?

 

Sure but they won't be in until Friday.

I haven't seen how the UM2 temp sensor works but in the UM Original it's a themocouple (not a thermistor) and there is a tiny board with a chip in the head that converts the thermocouple voltage to a voltage between 0 and 5V to indicate temps of 0 and 500C. Linearly. I assumed the UM2 is the same. I get temp errors when the cable running from the head to the PCB has an open.

The print bed I'm sure has a thermistor as it doesn't get as hot as the nozzle and so thermistors are more appropriate here.

Does the bed heater work? Go to advanced menu and mess with the build plate temp.

 

[gr5 2,172]

So typically if you push the print head around by hand to the 4 corners it will fail in one of them (if you have an intermittent connection).

 

[fatalerror3141 0]

I cannot access any menus, the printer gets the error in its initial setup. All I can do after that is turn it off.

I think the amp for the thermocouples are on the PCB. I can see little IC's behind each temp port. Maybe one of those is dead?

The bed does not try and heat up, but I think this is because ive not reached it in the setup yet. It's temperature probe does have the same resistance as the nozzle though which would suggest another thermocouple?

I have work tomorrow so will play with it some more Saturday.

 

[illuminarti 18]

Looking at the configuration.h for the firmware, both the extruder and the bed are marked as using the same type of temp sensor:

PT100 with INA826 amp in Ultiboard v2.0

 

A PT100 is a type of RTD resistance sensor. PT indicates a platinum base, and 100 (ohms) is the nominal resistance at 0ºC. And the standard is .385 ohms/ºC. So the 108 ohms that you saw would be a touch under 21ºC.

 

One thing you might try is hooking the printer up to a computer over USB, and using Pronterface or Repetier Host to see if it will report temperature data back over the USB link, to see what is going on.

 

[gr5 2,172]

So the 108 ohms that you saw would be a touch under 21ºC.

 

 

So the thing to do next is to cut power, hookup the ohmmeter to those wires at the PCB (with the cable disconnected from the pcb) and then push the head around the bed into the 4 corners to see if there is an open in one of the corners - that's what I'm expecting as you are stressing the wire in different directions as you move the head around.

It's okay to push the head around with your hand.

 

[fatalerror3141 0]

Thanks for your help guys.

I think I've found the problem, it is an internal connection issue within the PT100 (right at the head). I removed it from the head. Moving the sensor around while measuring the resistance I get an intermittent connection or it just stays Open circuit!

This is strange as the head is not moving, just heating when I get the error, unless the expansion from heating alone is causing an intermittent connection.

 

I installed Pronterface. Nice program, its able to move the head around even with the error onscreen. But I could not get it to show any temperature readings from the bed or head. When the printer oled screen shows the error Pronterface says "Extruder switched off MAXTEMP triggered".

EDIT: Pronterface is giving me control over and showing the temperature now. And it appears to be holding at 185*c. I will try printing something.

 

 

[fatalerror3141 0]

Ok, It is still not functional.

I managed to get some life out of the sensor but after increasing it from 185*c to 200*c just extruding filament through Pronterface (not printing) it died again, reported head temp was 1000*c at one point, Clearly a connection issue within the sensor itself. I have also tested the bed in Pronterface and it heats fine.

A couple of other problems have arisen during this test, that include the head hitting the frame during the filament insertion step (on the ultimaker not Pronterface). I may have solved this by moving the end stop switch back a bit.

The lights inside the unit were "flickering" when I had bed and nozzle heat on in Pronterface. The Psu brick was also making a clicking noise during this. Its almost as if the voltage was varying or current was to much.

Also there is still the problem with the hot running controller board, it works fine but sits at 80*c. No heat sinking on any IC's.

I can heat sink them no problem, but should it have already been done at the factory?

Thinking of returning it for replacement. I might have better luck.

 

[gr5 2,172]

ic's at 80C sounds fine. Even 100C. Head hitting side - sounds like you fixed it. Flickering lights is normal when bed is within about 10C of goal temp. It is PWM controlled meaning it turns on and off about 5 times per second which is visible and a little annoying (you can dim the LEDs if you want). I have never noticed any clicking sound from my PSU but I will check it next time.

The head temp probe is definitely a problem. I recommend you contact support at support.ultimaker.com and get a new probe/cable assembly on Monday. You could get a whole new UM but it may have new issues. Better to fix the 1 thing that doesn't work.

 

[fatalerror3141 0]

Ok, im glad the flickering lights are normal, i was worried it had another problem.

 

I moved the limit switch back for the Y axis. The head still touches the frame at the front of the printer, but the stepper does not stall anymore, Is this ok? Im not going to be printing that close to the edge anyway, but will it affect anything else now i have moved the position of the switch?

 

Ic's at 80*c is a little to hot for my liking. I bet stepper drivers at 100*c would be getting close to thier thermal design limit. Don't forget i was measuring the back of the board with an ir gun, not very accuate on a tiny surfacemount. The chip would likely be hotter.

 

I will get the new probe as you suggest, it would be better than getting a new unit.