Hi all. Just phoning in to the mothership for advice.
Original (Kickstarter) Snapmaker 2.0 A250, original rails and PSU and everything pretty much, but upgraded 2nd generation print head with the extra vents. Used about 80% for 3D printing 20% for lasering with the 10W laser head.
Starting to give me “Power Interruption” failures occasionally during print. Twice in a 4 hour print yesterday. Yet power did NOT bobble in the room (working on computer next to it just fine, plus everything is on a UPS). When the power to the printer enclosure clearly dropped it seemed more like the controller or Can-hub chose to ‘reset’ – the PSU light was steady, the printer stopped moving, lights out, then touchscreen went into a reset and after it started up again, it did offer me the print resume, and succesfully resume.
Aside from pulling every power/control cable out and reseating it a couple times to scrape off any accumulated surface corrosion and make sure nothing has worked itself loose, any suggestions beyond that for diagnosis?
I have made small mods to the PSU – interrupted the wall line-in so I could cable in a screened power meter looooong ago, and more recently I did swap out the fans in the PSU and remove some of the front light diffusion / stuff to give it better airflow. But by more recently I mean a year or so now. I don’t feel like either of those is related, as I said I could see at a glance when the power ‘fail’ happened the PSU was fine - something in the machine went down instead.
Bed heater cable was one of those early fail mechanisms and mine still looks fine where it comes out of the back of the bed, no sign of kinking, rubbing, or stress I can see. Nothing was abnormally warm to the touch (all rails do get warm during printing, of course, as well as the print head, I mean fondling cables and all I didn’t feel any that felt hot at all).
That’s difficult to diagnose IMHO… so many potential causes! I guess I’d start at the USB connector of the touch screen - is it still well seated? Can you provoke the problem by touching/slightly moving the USB-C plug of the touchscreen? Next I’d monitor the voltage of the printer (main 24V power rail) with a multimeter. In case you have a possibility to data-log this, that would be ideal. It would allow you to detect fluctuations in the main power line. I might also disassemble the PSU and look if some electrolytic capacitor shows ageing (i.e. a bulge at its top), Also, I’d check the cable that comes from the PSU - I never checked, but I assume (really do not know!) that one of the thinner plug pins carries the “power good” signal of the PSU, which I suppose is used to trigger power loss detection. I’d check if this is still having good contact or a break in the cable.
Well, crud. Now I’m thinking something in the [correction] Controller is close to failing. Stress fracture in the board or solder joint or something?
I unseated and reseated all cables (power off of course). The main PSU cable was a bear to pull out, and reseat. At first the machine didn’t even come on when the PSU was turned on afterward. Wiggliing the main power cable I could see the little slow-pulse light around the USB port flicker a tiny bit.
Off, reseated again, it came on and the motors made their initial engagement thunk, USB port breathing light on, but no touchscreen. Off, unplugged touchscreen for a little while then replugged…this time it booted normally.
The USB3 port for the touchscreen is pretty loose feeling, as is the USBA plug in for the memory stick. Heating the bed now for another test print but starting to feel like I should put a new main [correction] Controller on order…it does seem like maybe intermittently losing the touchscreen connection could have been the mechanism. Just ‘wiggling’ that by hand (without trying to pull it ‘out’ any) while it’s been heating next to me didn’t get it to reset though. (Stressing the right angle molded end at the touchscreen also causes nothing, and feel pretty solid…I’ve always babied that a little.) So I’m wondering if it’s more of an ‘under stress’ failure (rails drawing, more overall heat, etc) than just the apparently loose feeling connection. The troubleshooting pages do seem to indicate that the USB3 to touchscreen was a weak point, maybe I’ve just been lucky all these years.
Starting a shorter print to see if I get another failure with movement and extrusion heating too.
EDIT - a 2 hr print went without flaw. I’ll repeat the 4 hr one it failed on before.
Thanks, I did see that. I am pretty certain I’ve never tried that and might if I see the failure again. So far today a 2 hr print and 4 hr print and no new interrupts. Doing a couple shorter prints for the wife tonight and then will be calling it for the workweek again…
