Printer screen crashes, displays random gibberish chars mid-print  

RE: Printer screen crashes, displays random gibberish chars mid-print

FINALLY someone other than me had this problem!  

Jim, I'm sorry you are encountering this but I've had the same problem for about a month and when I contacted PRUSA support they said they had never seen it before.  My situation is that:

1. This happens on both my MK3S-MMU2 and MK2.5S.
2. It happens with both the 3.8.0 and 3.8.1 firmware.
3. It happens with code generated with both the 2.1.0 version and the 2.0.0 of the PrusaSlicer.
4. It happens both when being run by an OctoPi (OctoPrtint) and from and SD card.
5. It happens on virtually every large print at random times.
6. When both printers are running at the same time they do NOT crash at the same time.
7. I've confirmed that is happens in single mode, but have not yet checked it in multi-extruder mode (just thought about it), however I'd be surprised if they are linked.  The models are all single color models and once the filament is selected they sit dormant for the rest of the print.

This effectively makes both printers very expensive pieces of junk that do nothing but waste time and filament.  Prusa support is normally very good at helping and in most other respects I love their products, but the last two times I spoke to them they didn't have any idea other than to re-seat the LCD screen cables, which I did.  I even tried wiggling them while the print was going to try and trigger it but that didn't work.

As you can tell, I am very frustrated right now because this is causing me significant issues with multiple projects for two different clients.  I'm about to contact support again and reference this post so they know it's not just me.  Thank you so much for posting!

Mark

RE: Printer screen crashes, displays random gibberish chars mid-print

For an extra datapoint:

• my gcode was generated in cura. So this doesn’t seem to be slicer dépendant if you’re also getting with with prusa slicer 
• I’m printing via an octopi

RE: Printer screen crashes, displays random gibberish chars mid-print

Mark are you printing via sd card? The crashed output looks a bit like a die reading so next I was going to try that instead of my octopi, but if you get the same via sd card seems like this won’t fix it

RE: Printer screen crashes, displays random gibberish chars mid-print

Marc with Prusa support was helpful last night.  He suggested we use Ponterface (or Octoprint) to watch the serial output (or octoprint.log / terminal output) to see what the error was.

It may be unrelated, but I'm having a MINTEMP problem with both printers.  It could be the cable or connections, or just that the room is a bit cool (65F / 18C).  

If you find out what your problem is, please post it here and I will do the same.

Mark

RE: Printer screen crashes, displays random gibberish chars mid-print

Actually I think mintemp errors could be related. I noticed on one of these failures the temperature graph on my octopi prior to failure was getting wonky.

so the bug could be that it incorrectly displayed the mintemp failure message in the new firmware under some circumstances 

RE: Printer screen crashes, displays random gibberish chars mid-print

This is looking more and more like a bug in the mintemp reporting. I got this screen again tonight, and you can see in the shot below that just before the failure the temperature dropped sharply.

The initial sharp temperature drop looks too sudden to be the heater. I'm starting to think that I have a faulty thermistor.

TLDR: Maybe the 3.8.x firmware crashes while trying to report mintemp on the mk2.5.

RE: Printer screen crashes, displays random gibberish chars mid-print

Can see quite clearly now from the octopi logs that when this happens, it is a bug in the reporting of thermal runaway:

RE: Printer screen crashes, displays random gibberish chars mid-print

Same thing happened to me, though it was not during a print, I normally keep my printer on in the basement, and it starts happening a few weeks back after upgrading from mk3 to MMU2S.

Since it was not printing, I can only assume it is related to the mintemp, since it can someone get quite cold in the basement

RE: Printer screen crashes, displays random gibberish chars mid-print

@jiminlondon

Do you set your bed temp to zero after first couple layers? Looks to me like your cable is broken und you're getting a thermal runaway. 

There might be some electrical spikes and because of that the display is going weird. Fix your thermal runaway issue and maybe this issue will disappear. 

RE: Printer screen crashes, displays random gibberish chars mid-print

I have had simular problems, but not in each point maching problems. It startet for me with very few screen errors like you showed. I think there is somewhere a thread of another guy "aliens has landed".

Then, suddendly after a long print (15 h +) i came home from work, the printer had about 4 h of idle. I had done work and ignored the printer, because i planed to print later a new thing. I realised becaus of the noising fan every few minutes, the printer ist constantly rebooting(the fans go about one secound full power by restart)

From this point the connection from raspberry pi 3b+ via gpio was not possible. When in poweres the raspberry with usb power, the printer restarted. 

I disconected the gpio, reföashed the einsy board several times, reseted it, but from this point it wasnt able to print no more. When i started a print from sd card, sometimes the screen freezed, and few secounds later the printer restarted. Sometimes the peinter loadet the gxode, but both the bed and extruder showed in the display roomtemperature/0. So the printer did not heated up. I tried it several times. I chated with prusa support, told them my thoughts that the einsy has to be broken. After more then an hour diagnostic they agreed and the send me a free new board. I flashed the newest firmware on it, and it run withoit issues with the same raspberry pi 3b+ as before, same xinfiguration. I had one more time since then a simular issue with cryptic symbols on the display.

Im not an expert but i think the problems started for many with the last firmware update look at the topics in this forum and the discord server, they are all simular, and all involve display errors.

One other possibility im thinking about now is maybe a slicer update, but in my memories the last update before the actuel one a week ago is long period of time. Thouggt maybe they started to implement the new previev function for the mini. There seems to be an embded png image inside the gcode.

RE: Printer screen crashes, displays random gibberish chars mid-print

I fixed the runaway and this problem is gone. It is a problem in the new firmwares with reporting of thermal runaway, I’m 101% certain of this now. What is the best way to report a bug like this?

RE: Printer screen crashes, displays random gibberish chars mid-print

I guess on github?

RE: Printer screen crashes, displays random gibberish chars mid-print

I had the same crash as you described.

I started checking the printer if all the functions worked correctly. There i found that the hotend did not heat up. One of the crimp connections next to the heating element looked totally normal but the connection was broked. I fixed that issue and now the printer does not crash anymore.

RE: Printer screen crashes, displays random gibberish chars mid-print

@jiminlondon

how did you go about fixing the runaway?

RE: Printer screen crashes, displays random gibberish chars mid-print

Had the same issue happen for the first time during the preheat phase on an Octo-pi. 

The issue happened before printing even started.

Model: i3 Mk3s

Location: Garage, Ambient about 8C.

Firmware: Just upgraded from 3.8.0 to 3.8.1.

RE: Printer screen crashes, displays random gibberish chars mid-print

Update:

Just had it happen 2 more times in a row during OctoPi preheat. 

Doesn't happen at all during prints.

Photo added for reference:

RE: Printer screen crashes, displays random gibberish chars mid-print

I am having the same issue.

I doubt this is a hardware issue... I got this error after some firmware update.

I think the people who think they fixed it by changing thermistors, settings or repairing cables are just lucky because it doesn’t happen all the time.

RE: Printer screen crashes, displays random gibberish chars mid-print

I too just had this issue on a longer print.  MK2.5, F/W 3.8.1  Printing from Octoprint, same file I've printed MANY times on this printer, on this firmware version.

>>>>Will this fix be in 3.8.2, and will it be released soon?<<

octoprint.log relevant section:

2020-01-30 11:32:57,790 - octoprint.plugins.navbartemp - INFO - Checking SoC internal temperature
2020-01-30 11:33:27,837 - octoprint.plugins.navbartemp - INFO - Checking SoC internal temperature
2020-01-30 11:33:57,881 - octoprint.plugins.navbartemp - INFO - Checking SoC int
ernal temperature
2020-01-30 11:34:27,929 - octoprint.plugins.navbartemp - INFO - Checking SoC internal temperature
2020-01-30 11:34:57,976 - octoprint.plugins.navbartemp - INFO - Checking SoC internal temperature
2020-01-30 11:35:21,419 - octoprint.util.comm - WARNING - Received an error from the printer's firmware: Temperature heated bed switched off. MINTEMP triggered ! - // action:cancel
| Last lines in terminal:
| Recv: ok
| Send: N130723 G1 X179.690 Y114.418 E0.21398*94
| Recv: ok
| Send: N130724 G1 X177.731 Y121.729 E0.25620*88
| Recv: ok
| Send: N130725 G1 X184.052 Y121.729 E0.21398*85
| Recv: ok
| Send: N130726 G1 X186.011 Y114.418 E0.25620*86
| Recv: ok
| Send: N130727 G1 X192.333 Y114.418 E0.21398*83
| Recv: ok
| Send: N130728 G1 X190.374 Y121.729 E0.25620*88
| Recv: ok
| Send: N130729 G1 X196.695 Y121.729 E0.21398*87
| Recv: ok
| Send: N130730 G1 X198.654 Y114.418 E0.25620*89
| Recv: ok
| Send: N130731 G1 X204.976 Y114.418 E0.21398*83
| Recv: Error:Temperature heated bed switched off. MINTEMP triggered !
| Recv: // action:cancel
2020-01-30 11:35:21,422 - octoprint.util.comm - INFO - Changing monitoring state from "Printing" to "Error: Temperature heated bed switched off. MINTEMP triggered ! - // action:cancel"
2020-01-30 11:35:21,435 - octoprint.util.comm - INFO - Force-sending M112 to the printer
2020-01-30 11:35:21,477 - octoprint.util.comm - INFO - Changing monitoring state from "Error: Temperature heated bed switched off. MINTEMP triggered ! - // action:cancel" to "Offline (Error: Temperature heated bed switched off. MINTEMP triggered ! - // action:cancel)"
2020-01-30 11:35:21,499 - octoprint.plugins.pi_support - ERROR - Got an error while trying to fetch the current throttle state via "/usr/bin/vcgencmd get_throttled"
Traceback (most recent call last):
File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/pi_support/__init__.py", line 263, in _check_throttled_state
state = get_vcgencmd_throttled_state(command)
File "/home/pi/oprint/lib/python2.7/site-packages/octoprint/plugins/pi_support/__init__.py", line 140, in get_vcgencmd_throttled_state
raise ValueError("cannot parse \"{}\" output: {}".format(command, output))
ValueError: cannot parse "/usr/bin/vcgencmd get_throttled" output: error=1 error_msg="Command not registered"

2020-01-30 11:35:22,907 - octoprint.plugins.tracking - INFO - Sent tracking event commerror_firmware, payload: {'commerror_text': 'Temperature heated bed switched off. MINTEMP triggered ! - // action:cancel'}
2020-01-30 11:35:23,280 - octoprint.plugins.pi_support - ERROR - Got an error while

RE: Printer screen crashes, displays random gibberish chars mid-print

Adding data point - I am getting the same problem. Octopi reports "MINTEMP error" and printer crashes with gibberish on screen. Happens at random times. Unsure of what to pursue for a fix at this time.