UM2+ Connect - Nozzle not heating up, build plate not moving

[ruttger 0]

Hi there, I am new here. My Ultimaker 2+ Connect stopped working. During quite a large print, the print head got clogged with filament.

 

From that moment it couldn't heat up the nozzle anymore. So I put apart the fans and used a heat gun to remove all filament. But didn't get it to work. The touchscreen is still working, but I can't move the build plate using the touch screen. Also when I start the printer, normally the build plate moves up and down a bit, but that's not working either.

 

In the mean time I've tried a lot of things: checked connections at the main board and build plate, replaced the heater+cable, replaced the nozzle, hot end isolator, TFM isolator coupler and heaterblock, reset to factory settings, updated to current firmware again (1.5.2). But no changes.

 

Only this morning; I turned on the power again, and the printer worked for about 2 minutes. I was able to move the build plate with the touchscreen and heat up the nozzle, but then it suddenly stopped working again. By restarting the printer I can't get it to work for a few minutes again. No error codes. I've added the log.

 

Hopefully you guys have any suggestions what I can do?

 

UM2C_Ultimaker-2C-529F_v1.5.2_2023-06-14_14-35.zip

[gr5 2,071]

You should contact your reseller.

 

So the steppers and the heaters run off 24V.  Everything else is lower voltage.  Losing 24V intermittently could be a firmware feature (maybe it sees crazy values on the sensors due to damage and so disables everything), or it could be a hardware issue that I'm familiar with.

 

If it's a firmware issue you can probably see something about it in the log file?  Something like "bad temp sensor value" followed by "disabling 24v" or "disabling heaters and steppers".  Just a guess.  You could also concentrate on print head temp sensor since it sounds like you may have damaged it - they are a bit delicate.  Before heating anything up, go through the menu system to control it manually and see what temp it is reading.  It should read at room temp (I assume around 20C).  If it reads say -100C, 0C 300C, or just "error" then you should concentrate on this.  I'd replace the sensor.  They are the most expensive part in the print head at around $25.  You can get them from UM resellers or from 3dsolex.com (same part as for UM2).

 

Anyway I want to talk about the hardware issue.  I've never seen the underside of a um2+c but I have a UM2, UM3, and an S5.  They all have a variation on this board shown below.  It controls the steppers and the heaters.  See that big blue box there?  That's the relay that allows 24V to flow to the stepper drivers and the heater switches.  You could give that a rap or assuming you only have access to the other side you could tap that corner of the PCB with a very fast, but low energy tap.  Like with a wooden spoon knocking quietly on a pan.

 

That relay is known to fail intermittently and you can bypass it with a jumper as it isn't really needed.

[ruttger 0]

Thank you for your extended response.

 

About the sensors, the heat sensor measures 29°C (which could be right because the outside weather is quite warm). Also when I warm it up with a heat gun, it measures higher temperatures, so it seems to work.

 

But what I saw in the diagnostics screen might be more interesting: the build volume temperature is 700°C (see photo). Which seems extremely high? I don't know what the 'build volume temperature' means, is that the build plate?

 

Would that mean I need to look into something else?

 

 

[gr5 2,071]

Two colleagues who know the um2+c tell me you probably have a "bad mainboard".

 

I just don't know the um2+c very well.  If you are competent with a soldering iron and multimeters I can offer some advice but if not I probably can't help you.

 

I don't know if the 700C is the goal temp (in which case maybe that's just a normal profile temp from cura) or (more likely) if it really thinks that is the current temp.  If it really thinks that is the current temp then you might just have an open in your temp sensor wire.  I don't know where that temp sensor would be located.  It's possible the printer is refusing to move any steppers while the internal temp is over some threshold.  Say 50C.  I know 80C air temp is hot enough to damage the steppers.

 

So it could be something very simple (loose wire to the temp "build volume" temp sensor).

 

I didn't even know the UM2+C had an air manager so I really don't know this printer very well.

 

[Torgeir 228]

Hi @ruttger,

 

Just found this parts catalogue for UM2+C.

I'll think @gr5 is right, -so maybe it's just the high temp value of the inside also act as a safety device shutting down the printer? One open wire in temp sensors often lead to extreme values, either hi or lo.

There's just enough in this catalogue to have a better idea of the location etc. The main board look some different..

 

Here it is:

https://www.farnell.com/datasheets/3761279.pdf

 

Thanks

Torgeir

[CarloK 201]

@gr5 To set a few things straight:

• The UM2+C pcb was slightly modified from the S3, i.e. the relay has long gone and several other improvements like replacing the stepper drivers by more quiet TMC2130 chips.
• The UM2+C has an optional filter, it is just a simple on/off mechanism based on buildplate and nozzle temperatures. When we developed it, it was not to be named an AirManager as it doesn't attempt to control the build volume temperature (for this the AirManager in the S5 has it's own processor). On release the Marketing department decided to name it AirManager anyway 🙄

In the log files I see the printer rebooting a few times, but there is no clue as to why it stopped. 

 

A temperature of 700C is reported by the temperature sensors when a wire is loose or broken. The sensor for the build volume is in the top of the housing, at the rear. You only see it when you know where to look, see attached photo. Check the connector here, you might have disturbed something here when using the heat gun. The temperature sensor is marked PT100. The other component is a reed relay, when you put a magnet there, then it should show in the display that an Air Manager is present (I think the text is only updated when you open the screen). This is a nice test to check whether the cable is connected correctly to the main board.

 

The UM2+C can't control the build volume temperature, i.e. the temperature inside the casing, but as a safety measure we do monitor the temperature. I don't know if the 700C is the root of your problems, but it's an easy thing to check for loose connections.

[ruttger 0]

Thanks a lot for your replies!

 

@CarloK I've checked the sensor for the build volume at the top, which seems to be fine. I need to try with a magnet later. 

 

On 6/17/2023 at 11:18 PM, CarloK said:

In the log files I see the printer rebooting a few times, but there is no clue as to why it stopped. 

 

Thanks for checking the error log.

 

In the mean time I've also replaced the PT100B temperature sensor.

 

After that, the printer worked for about 10 minutes again. The print bed + print head moved to their starting points when starting the printer. Also the nozzle heated up via the menu. And the 'build volume temperature' in the 'diagnostics' menu was normal (I think something like 25°C). I even restarted the printer and it still did work like it should.

 

So I decided to lubricate the axles (as it was needed according to the maintenance schedule) before I started a print.

 

But after that (maybe 15 minutes) it suddenly didn't work anymore: nozzle couldn't be heated anymore, 'move build plate' didn't work anymore through the menu and the 'build volume temperature' was about 230°C, but not 700°C,  don't know why this changed.

 

Because everything works fine for a short while, I feel like it's nothing with the hardware? Could it be in the software? Any other ideas?

 

 

[Torgeir 228]

Hi @ruttger,

 

When you started, the "build room" temperature was 25 deg. C.  The temperature to trig stop is unknown for us

If I'll give an estimate, -that will be around 100 deg. C maybe a little more -but certainly not 250 deg. Celsius!

 

Edit.

I've changed quite a few of this type (PT100) of temp resistor, and what you see here is just a common thing.

 

I'm quite sure this is your problem, -however in theory other thing can fail, but this is no1 to suspect.

This is a surface mounted platinium resistor (PT100), and quite easy to change if one have the tools/skills to do this.

Otherwise this little PCB cant be very expensive.

 

Here is a cut out from picture given by @CarloK showing the parts:

 

 

Thanks

Torgeir

 

Edited June 23 by Torgeir
More info. And more..

[Torgeir 228]

Hi @ruttger,

 

Hmm, did not read your posting good enough, maybe I'm getting to old.. 😕

Did you change the whole PCB? Or just the PT100B?

Is the UM2C+ meant to wear the "environment" hat always on, or can you remove the "hat" at will?

Just come to think that, if you remove the "hat" -the software would deselect this temperature sensor.

Also wonder about the fan used for venting. Some fan types are notorious for making electromagnetic noise spread around their wires that can block other low signal amplifiers such as the input from the PT100.

There might (?) be a way in the firmware to deselect this sensor, at least as a test?

 

Just my 5p.

 

Thanks

Torgeir

 

 

 

[gr5 2,071]

It's not the software.  It's the reading of the temp sensor for sure.  Look at the reading of the sensor live while jiggling the wire both near the sensor and underneath the printer.  Somewhere there is a loose connection to that temp sensor.  Once the resistance goes up then the printer will refuse to move servos or heat the bead or heat the nozzle.

 

You can measure the resistance.  It should be around 109 ohms for room temp.  You can find a pt100 resistance versus temp table by googleing it.  All pt100 sensors use the same table.