A350 stops at random without errors, resumes fine

Snapmaker 2.0
1

I have a really old A350 that’s from the very first batches. It has worked fine for years, until recently it started pausing jobs for no apparent reason. From Luban’s point of view it’s like it went into filament runout state, except there’s no message about filament running out nor it has actually ran out. In the job status field the Run-button is active and the machine happily continues once it has been clicked.

Am I seeing a filament runout sensor failure or could this be a software issue? I found many topics about same thing happening, but in those it was stuck at filament runout state even with filament or it wouldn’t just let continue the print. This one lets me continue instantly. The device’s screen looks normal for the state where it’s connected to Luban.

I have the latest firmware as of writing this and Luban 4.13.

2

Difficult to say, but if you can Re-run from Luban and it continues, I think that a faulty filament sensor is a likely reason. I could imagine that the sensor triggers, then falls back and the message disappears, and the machine is waiting for you to continue.
To check, I think there are guides how to check the filament sensor for both the old and new print head. The new, DX head had issues and a replacement of the sensors is recommended, for the old it may be enough to just bend the switch flap a bit.

3

Check your logs or share it, maybe there is something to find.

I remember a nearly similar behavior with my 200W CNC head, it got blocked while milling so the machine got to no continue able pause state (fail was only visible in the logs) .