[BUG] Extruder Motor still stops

[Gik-0101]

Printer model

XL Multi Tool

Firmware version

6.2.0 RC1

Upgrades and modifications

Fan Shroud 360, Enclosure

Printing from...

Prusa Connect, USB

Describe the bug

Extruder motor still stops at the layer height where the component fan switches on.
Mainly affected tool head 2
Dwarf cover connector has already been removed (recommended by support).

It doesn't matter which material is printed.

Thanks to FW 6.2.0 RC1 now i get a "red screen" and the Printer stops.

How to reproduce

Not reproducible

Expected behavior

No response

Files

No response

[3Dwyer]

I'm having the same issue. Firmware did the same thing for me as well. Just gives a red screen that extruder stopped. Support sent me 2 new extruder motors and 2 new extruder cables. They had no affect on the outcome.

[balloonhotair]

I just installed this version of the firmware and got the same error message 4 hours into a 12 hour job. What is worse now is the error message is the end of the job. In the previous version if I noticed this bug I would pause the XL and hit the nextruder reset button on the side of the toolhead and once the rest was done I could resume the job and the extruder would keep going. I would like to see them do the same in the firmware as a workaround while they try and find out what is causing this bug.

[CloudStrife1983]

In my opinion, the various errors such as: Extruder stops, Nozzle LED flickers strongly and also the Min Temp errors that suddenly occur at work, which occur sporadically on 3 of the 5 extruders without forewarning, are all related. The contacts of the plugs simply deteriorate due to a lot of movement, which leads to the problems mentioned. Prusa absolutely must make improvements here. This is simply a design error. The plug needs a reasonable and reliable strain relief.

[Gik-0101]

I've been bothered by this problem since August (I think) 2024.
I have the normal pulsing of the nozzle LED when heating up and holding temp., but if the extruder fails it strobes very quickly.
But I've never had the minimum temp. problem.
Without starting a technical discussion here, I don't know that much about the XL. But I think the problem lies deeper than a plug connection. I couldn't trigger the error by moving the plug connection while printing. It shouldn't be purely a software problem either.
Anyway, I just want a solution slowly.
That's why I opened the error here.

[balloonhotair]

Yes I agree with everything you said above. I have looked at the code changes that the developers made in the last release to address this issue and at a high level they are dealing with race conditions with locking semaphores. It is what can be called a starvation problem and when it happens the current code has no recovery way out except for now putting up an error message, which has the comment in the code "Never should get here". LOL So this issue is probably both a hardware issue and a software issue since it is so "random". Like I said above instead of the error message the printing should pause and then a reset of the ARM processor should be done and then a resume, at least this would let then print continue. IMO.

[Gik-0101]

Yes, that would be a sensible and intelligent interim solution to avoid always producing incorrect prints and wasting material.

[bkerler]

My best guess from my experience is that this isn't a software issue, but hardware issue. If the error occurs randomly, it might be PSU or XBuddy Board related. Check all cables for broken shielding and also that all connectors are connected properly. If all that is fine, I'd recommend to replace the main board.

[jxtan-msn-com]

I have the normal pulsing of the nozzle LED when heating up and holding temp., but if the extruder fails it strobes very quickly.

Just got hit with this issue, and I also noticed that the extruder LED light pulsing. It was working for awhile, then new print, this happens. And after stopping the print, the purge filament won't work either until I reset the XL.

[balloonhotair]

Just FYI if you notice this when printing and not using this RC version of the software you can pause the print from the console and hit the reset button on the left side of the extruder. This will reset all the extruders to blue and then green color. Then a resume on the console will start the print again from where you paused it.

[CloudStrife1983]

My best guess from my experience is that this isn't a software issue, but hardware issue. If the error occurs randomly, it might be PSU or XBuddy Board related. Check all cables for broken shielding and also that all connectors are connected properly. If all that is fine, I'd recommend to replace the main board.

These are all things I have already done. I have already installed a new sandwich board. Nothing had helped. Simply reconnecting the plugs solves the problem of the extruder stopping for quite a while for me. However, the flickering of the nozzle light remains very minimal and becomes more intense the more I print.

[jxtan-msn-com]

On the facebook group, someone said it is related to bad extruder cable.

My best guess from my experience is that this isn't a software issue, but hardware issue. If the error occurs randomly, it might be PSU or XBuddy Board related. Check all cables for broken shielding and also that all connectors are connected properly. If all that is fine, I'd recommend to replace the main board.

These are all things I have already done. I have already installed a new sandwich board. Nothing had helped. Simply reconnecting the plugs solves the problem of the extruder stopping for quite a while for me. However, the flickering of the nozzle light remains very minimal and becomes more intense the more I print.

On the facebook group, someone said after working with support, that specific case is related to bad extruder cable.

[Gik-0101]

IF that's true, hopefully those of us affected will hear something from support soon.
My support just told me yesterday that some things are still being tested internally. But it will soon be completed.
Let's see, I've already been promised a lot in this direction.

[balloonhotair]

Well I finally have a workaround that for me seems to prevent the extruder motor stalling. I have a job that I have tried to print almost a dozen times in the last month or so and it always fails with one of the extruders not turning. I also had the flashing led issue but it was not my focus since the extruder motor stalling was a bigger problem. I have now run the 12 hour job twice without any issues and the flashing led is no longer an issue as a bonus. I created my own strain relief for the cable and connector. It is crude and I suspect Prusa will have a nicer way of doing it soon. I attached a picture of what I have and hope it will help someone else.

[CloudStrife1983]

On the facebook group, someone said it is related to bad extruder cable.

My best guess from my experience is that this isn't a software issue, but hardware issue. If the error occurs randomly, it might be PSU or XBuddy Board related. Check all cables for broken shielding and also that all connectors are connected properly. If all that is fine, I'd recommend to replace the main board.

These are all things I have already done. I have already installed a new sandwich board. Nothing had helped. Simply reconnecting the plugs solves the problem of the extruder stopping for quite a while for me. However, the flickering of the nozzle light remains very minimal and becomes more intense the more I print.

On the facebook group, someone said after working with support, that specific case is related to bad extruder cable.

He was probably just told by support to "swap cables". After that, it's always gone for the time being. As long as there is nothing official from Prusa about this, it's just hot air for me. @GiK: Many people in the forum have already swapped cables and it didn't help, if I'm not mistaken.

Replacing the Dwarf cables is always the first thing the support team suggests. It may also work better at first because the cable contacts are still unused. However, this does not change the cause of the problem, which in my opinion is not the cables.

[Gik-0101]

I am with you 100% @CloudStrife1983
I've been struggling with this error for a long time and have also agreed with Prusa Support that I won't take part in this material battle. If the error has been clearly identified and if it is a hardware error then I would like to have the revised component for replacement. I don't mess around with the same faulty parts beforehand. I want to print and not just repair.

That's why I said we'll see. A lot has already been said. Let's see what really comes and is true.