I recently got my printer switched over from a Mellow sb2040 v2 to an sb2040v3 to make use of it's extra can port to also install Cartographer. I got everything running well, it prints beautifully, but on longer prints it's been consistentnly failing with a "Lost communication with MCU 'sb2040'" error.
This usually happens a few hours in, but the print i attempted after adjusting some cables around under the deck got nearly halfway through a 20 hour print before it failed.
I was wondering if there was anything indicated in the klippy.log that could give me a clue before i go replacing hardware yet. I don't have a great idea what any of the info means when i throw it into klipper log visualizer, the only thing i notice is the TX Retries for the sb2040 steadily climb throughout the print until the shutdown, but as i understand it that doesn't really mean anything?
any help is appreciated~
#Lost communication with MCU 'sb2040'
north wraith
golden talon
one of the telltales we can see sometimes is an increasing bytes_retransmit rate
quickly scanning yours, that doesn't seem to be the case
north wraith
it seems to only rise after it shuts down
potentially dumb question
as i understand it, not having proper stress relief can cause this potential issue. I have a pug mount on both ends of the umbilical, but the pugs i printed clamp pretty tightly, that couldn't be a possible cause could it?
golden talon
they need to grip tightly to work
as long as the cable on the device side of the PUG can't move, they should be good
what's interesting to me actually is the tail off in system memory use to almost idle just before the crash
can't explain it, but its an unusual enough pattern to comment
north wraith
yeah i have no idea about that
it's worked perfectly up until i switched over to the 2040 v3 with carto
i did switch to a 90 degree angled umbilical cable for z chain clearance, so i guess the next thing i can try is swapping out the cable.
could having the canbus signal wires run close to the 5v power supply or near the motor wires potentially cause an issue?
i ask as i had to reorganize some wires due to my touchscreen flickering as the ribbon cable was going between some of the motor wires
golden talon
As long as the can wires are twisted along their exposed length they should be ok
north wraith
oooh, they are not...
time to flip the printer over then