Crash right after Z height check on self test  

RE: Crash right after Z height check on self test

Do a cold pull and post a photo.  

RE: Crash right after Z height check on self test

@cwbullet

I'm way past that, unfortunately... hot end is new, nozzle is new, etc. I am hoping to try to load filament but the printer crashes anytime there is an attempt to communicate with the extruder, or such is my guess.

By "crash" I mean the printer reboots without any warnings.

RE: Crash right after Z height check on self test

Posted by: @gregfridman

Hi.

My Mini started jamming filament. I see it was getting stuck in the hot end and not extruding.

1. I cleaned everything in the hot end as best as I could. Problem continues.

2. I cleaner the hot end, removed all stuck filament, dusted/cleaned the extruder. Problem continues.

3. I purchased a new nozzle, cleaned everything. Problem continues.

4. I purchased a new hot end, installed everything. Now the printer crashes during self-test, right after it's done checking Z.

Any ideas what I could do next? I reset the firmware, running 4.2.1 now.

I would also check the height adjustment of the MINDA probe and the extruder drive:

https://help.prusa3d.com/en/article/clogged-nozzle-hotend-mini_112011

https://help.prusa3d.com/en/article/m-i-n-d-a-sensor-testing-mini_134021

https://help.prusa3d.com/en/guide/how-to-adjust-the-height-of-the-m-i-n-d-a-sensor-mini_154547

RE: Crash right after Z height check on self test

@karl-herbert

Thank you very much!

I already did all the steps in the Clogged Nozzle article. The MINDA sensor looks good, too.

I can raise and lower the temperature of the nozzle with no problem. X-Y-Z movements are fine.

I go to Filament -> Load filament -> PLA; printer clicks and immediately reboots.

I'm not sure what I can do at this point.

I checked all the connections as best as I could and everything looks fine to me...

RE: Crash right after Z height check on self test

Sorry there were a lot of updates while I was writing, so I updated my post

Also the USB sticks that were provided with the MINI were reported to be faulty. They are known to be the cause of continuous crashing but its usually during a print and not during calibration. Are you using that one?

RE: Crash right after Z height check on self test

@3dprintedgr

Dang! I really hope that's the problem... yes, I have the original USB plugged in. The printer is at my office and I already went home. I'll test it out tomorrow. It would be silly if that's the cause of this 🙂

However, why I think that's not the case: I've repeated this at least a few dozen times. When I run self-test, the printer reboots immediately after the Z-axis check is completed. Also, the printer reboots when I try to load filament, as I mentioned, right after I click "PLA" in the filament selection printer reboots.

Is there a way to submit a support ticket?

RE: Crash right after Z height check on self test

@gregfridman

Defective thermistors can also cause watchdog issues or reboots.

Use a hairdryer to blow hot air at the heatbed or hotend.

In the meantime, check if there is any temperature change on the LCD screen.

RE: Crash right after Z height check on self test

@karl-herbert

Good point!

RE: Crash right after Z height check on self test

@karl-herbert

Will do it tomorrow. When I was testing the new nozzle, I set temp to 215C, watched it go up without any issues, and measured it with my IR heat gun to be in that range

RE: Crash right after Z height check on self test

Also judging by your description the problem might be in your extruder motor. If you raise the temperature from the menu and then move E from the move axis menu, does it produce the same error?

If yes then check your extruder assembly for any stuck filament. Maybe there is something that blocks the filament spur from turning.

RE: Crash right after Z height check on self test

@3dprintedgr

Or the screws bring overly tightened.  I had a warped part and overly tightened.  It made terrible noises and would not extrude.  

RE: Crash right after Z height check on self test

@3dprintedgr

OMG! This might be it! I'm tempted to drive to the office right now but laziness overcomes...

I'll test this out tomorrow, thank you

RE: Crash right after Z height check on self test

@gregfridman

Lets us know the outcome.  

RE: Crash right after Z height check on self test

So-far so bad.

• Boot the printer
• Set nozzle to 215C and bed to 60C
• Once hot, move X, Y, Z, and E all work well. No clicking no problems.
• Run the wizard and get error at the very end (this time got through the whole test!!): The selftest failed to finish. Double-check printer's wiring and axes. Then restart the Selftest.
• Checked all the wiring as best as I can. Plug out and then plug back in all the axis.
• Boot the printer, repeat all the above procedures. During the selftest the printer rebooted after it cooled the nozzle to 40C......

No idea what to do now

RE: Crash right after Z height check on self test

@gregfridman

I would turn to the Prusachat with these pictures. Just log in with your Prusaaccount and choose the eshop. After a few seconds the chat window appears in the lower right corner.

I would be curious about the feedback!

RE: Crash right after Z height check on self test

@karl-herbert

Gotcha. Thanks! I'll be trying that tomorrow

RE: Crash right after Z height check on self test

@karl-herbert

THREE HOURS on support chat, making videos for them, etc. Resolution: send the board to them for testing and they'll send me a new one.

Sigh

When my Makerbot Method malfunctioned they sent me the whole new printer...

RE: Crash right after Z height check on self test

@gregfridman

That is very troublesome. I believe that Prusa does not know the cause itself and tries to change the board. But I don't think that this is the solution and I think that they have to search in the firmware.
This is only my humble opinion, but we will see then.

Good luck with this!

RE: Crash right after Z height check on self test

@karl-herbert

I hope you’re wrong.