Weird errratic behavior - RAMBo or LCD module issue ?
PRUSA i3 Mk2 with MMU 1.0 fw 3.1.0
Was working fine until a few days ago, no hardware or fw change since 2 months.
now during the print the head suddenly goes to X=0, then goes back to printing position and resumes printing;
does that a few times and then do the same to Y=0 and resumes;
after a while the print just hangs.
gocde looks ok, and same behaviour with a older gcode printed several time.
Selftest runs ok if done right after power-up and a few minutes of cool down.
Selftest fails if done after pre-heating, with error message about thermistance;
SD card content is fine at power-up; progressively the lines turn into garbage after several minutes.
The same with a different SD card, both SD cards ok on PC.
Looks like an electronics issue: RAMBo ? LCD module ? Power supply ? Something else ?
Help needed ...
Philippe
Re: Weird errratic behavior - RAMBo or LCD module issue ?
Turn off crash detection. But ideally, ensure you are printing in hi-power mode.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Weird errratic behavior - RAMBo or LCD module issue ?
Hi Philippe,
have you tried moving the extruder from side to side, and the bed from back to front, to ensure you have free movement?
it might be beneficial to lubricate the smooth rods with light oil first and work it in, by testing the free movement of bed and extruder,
check that your extruder cabling and heatbed cabling, are not catching on anything and also check that your extruder is clamped firmly in the extruder housing and your part cooling fan shroud is not drooping
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Weird errratic behavior - RAMBo or LCD module issue ?
Thanks for your answers -
Checked free motion of X axis and bed ok and added lubrification
cables are not catching on anything
Could not find crash detection in menus of my Mk2 - is it a Mk3 feature ?
Tried with Power mode - no change;
only mechanical issue found is the head cooling fan slightly damaged on a blade (don't ask how it happened 😳 ), indeed recent event, causing vibrations of the whole head assembly ==> replacement fan ordered.
How could this vibration cause those symptoms ? could it trigger a random autohoming on only one axis ???
Philippe
Re: Weird errratic behavior - RAMBo or LCD module issue ?
Success - I replaced the damaged left fan, and now works fine as before.
Lesson learned: never tolerate vibrations 😳
Thanks for your replies - it helped a lot.
Best Regards & Happy Printing
Philippe