Crashes, (forced) reboots and weird symbols on display
I have been using my Pruse i3 MK3S, and it has worked flawlessly for ~3 months. I use OctoPrint on a Pi3B(+? can't remember), and I have it in an enclosure in the shed (temperature in shed currently ~3-7°C, humidity is fairly high, but certainly lower that outside the shed) with both the power supply and Raspberry Pi outside the enclosure.
Lately, it has been behaving kind of odd. It has started to crash every time I print (sometimes during the 9-point pre-print calibration, sometimes during the print, rarely at the same time/place during the same print, but often the same few places if crashing during pre-print calibration). And often (if not always) when I start a print from OctoPrint, the printer (not OctoPrint, only the printer) will become unresponsive, and the reboot itself. (It seems like this reboot startup takes longer than I'm used to?)
Things I've tried/verified:
- Upgrading printer firmware (now I'm on 3.8.1, the issues were the same before and after this, and I've tried everything listed below both before and after upgrading).
- Cleaning out any filament debris within the enclosure (there was almost none, and none in the vicinity of belts/motors).
- Manually moving extruder/build plate back and forth. There is no resistance.
- Removing USB cable (OctoPrint) and printing directly from SD card (this didn't change anything, but I did notice a weird thing with the screen - maybe it was always happening, and I only saw it because I was physically at the printer when not using OctoPrint? See image below).
- Re-calibration (like the first time, calibrated everything). I haven't moved it at all between when it worked, and when it didn't, but I tried anyway. No effect.
I hope someone has an idea of how to fix this?
Screen sometimes shows weird symbols:
Video of an example of a crash during pre-print calibration (crash at ~22 seconds, just after calibration starts (~20 seconds). It continues after the crash, and it is not the extruder crashing):
i had the same issue (see attached image). My i3 MK3s stopped at first z-layer with the same screen and was dead. After a force reboot (X-Button) the display shows ERR-MINTEMP.
i unplugged the thermistor for the hotend and it was really dead. i'm waiting for warranty-replace (tomorrow) and will try to continue ..
Thanks, I've also reached out to Prusa now.
Please do update when you receive the thermistor, whether or not this fixes the problem!
Hi, i just replaced the thermistor and calibrated everything. Right now, it Prints ok and everything looks good.
but before replacing your thermistor, make sure it's really broken.
Follow this to measure your thermistor:
Very nice, thanks!
I got a reply from Prusa with a list of things to try. I'll leave it below, in case anyone else needs a troubleshooting guide.
(I just had a baby, so not sure when I'll have time to test, but I'll update this post when I do)
Highly delayed answer, but after going through most of the troubleshooting suggested by Prusa, I did see some high resistances (especially for the thermistor). I left it for a bit, while occupied by other things, and when I came back and wanted to measure again, and note the exact values, they had decreased significantly.
I tried rebooting, and starting a print, and everything's been working fine for weeks now. My best guess is that perhaps the humidity in the shed was a bit high (it had been in the 90+% for many weeks when the issues started, and is not ~70%).
Not sure what else to say, I disassembled most connections, re-tightened them (but this in itself didn't fix it), measured resistance in thermistor and heat bed, but didn't change anything else, as far as I can tell. Except the weather, since it is in a non-heated shed. It never freezes, even when it does outside, but the humidity seems to follow the outdoor humidity.
Sorry if this doesn't help you.