MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking  

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Mine is mk4, still had the issue. I went back to previous firmware and no issue since.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

I also have the stuck parking issue after updating to 6.4.0. Printing the same object, multiple copies, updated the firmware in between copies 1 and 2. No issues with first copy under old firmware, 6.2.6. First attempt of copy 2 after update got to 48% complete, then decided to reload filament for reasons. Parked, filament reload stuck at 98%. Power cycled printer after 10 minutes of waiting, did not resume print. Second attempt got to about 30% complete, filament reload attempted, parked, reload stuck at 100%. Power cycled after a couple minutes, did not resume print.

Reverted to 6.2.6, completed copies 2 and 3 without incident.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

I love how this issue made it in the final version, even though it had been reported on. They should have at least, mention it as a "known issue".

Had my 8h print stop halfways for whatever reason today.
When i came in to check, i found the printer had cooled down, and i got "Filament widerladen, 100%, Parke" (reloading flilament, 100%, parking" after i restored the heat. The filament was still loaded in the extruder, and there was no reason, why it should had been unloaded in the first place.
Thes same print ran without issues the night before.

Seems like i will have to downgrade my FW.

MK4 +MMU3 (FW6.4.0), print was single colour, PETG from spool 3

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

I've got the same issue here, it only happens when I try to start a print with filament already loaded in the nozzle. I was able to get it to work by having it unload the filament and reload it when the "filament already loaded" prompt pops up. 

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

And it’s still happening… https://forum.prusa3d.com/forum/postid/772875/

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Same problem here with my MK4+MMU3 using the 6.4.0 STABLE firmware. Very annoying...

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Posted by: @jgeiger2024

Printer gets stuck with status of 99% Parking.

After starting a print, the temperatures reach preheat, bed leveling executes, extruder heats to temp, extruder produces purge line at the left front of the build plate, then lifts and moves to the right.  Sequence halts at the 99% parking state.  The only recovery is to RESET.

Anyone seeing this?

Same problem!

Although what I wondered is if anyone also hears the MMU3 stepper trying to pull out the filament from the extruder, but fails to do that? As if the extruder stepper in the Nextruder is not pulling back the filament enough... at least that is what it feels like.

When I make cold pulls with the printer (i though it was a clog at first), the nextruder pulls out enough filament no problem with no clog...

On a side note: I opened up my gearbox and saw the lubricant was quite black and dirty. cleared all that out with IPA, re-calibrated but I see no change in the error or bug. So i think it cannot be that physical problem.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Today I updated to the stable version. The same problem...

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Can confirm this still occurs on the current firmware.

Really frustrating that Prusa and other users will point you towards the GitHub which I have done, but this has not been addressed or even a “known issue” yet.

This happens even during prints while running single colour through the MMU3 and will brick a print.

You cannot recover from the pause when this happens and there is no prompt to bypass it.

Strongly considering offloading my Prusas after this experience as it is very disappointing to have this issue over 3-4 software updates.

RE:

A slight variation in my case: it (very rarely) freezes 100%. The helpline suspects a network problem (Prusaconnect), but it also happens with a USB drive.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

I was going to simply bump this thread and ask how can I provide useful info the repo, then I realized, oh yeah... probably take a look at the issues. So FYI, yes this has been officially reported, here's one issue: https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/4918

It hasn't been reviewed by Prusa yet. Temporarily downgrading to https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.2.6 is currently working for me at the cost of some of the new timing saving improvements of 6.4.0.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

As it seems to only affect MK4S printers with MMU3 and since MMU3 is being neglected in favor of INDX, I expect this bug may never get fixed, or at least not soon.  It took Prusa more than a year to address the MMU3 overcurrent bug.  I, and others, have posted a complaint on GitHub which, oddly, is Prusa’s preferred medium of feedback but if they’re not addressing it there, I don’t know what else to do.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

I guess I got lucky? At 26 hours in (24%), I had the same issue. After reading this post, I decided to try unplugging it for 5 seconds and plugging it back in. It resumed the print (thankfully!), but it was weird... It moved to the rear of the purge block, about 2 cm above, and purged out some filament, several back and forth rows... It then lowered to the correct height and resumed printing. Not complaining, just weird.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Ugh... I just upgraded my MK4 w/MMU3 to the MK4S w/MMU3 and of course I started to get this error. It has ruined a few prints now that were 8+ hours in and at 95%+ complete. 

PRUSA really needs to address this quickly.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

@Bytor, you should downgrade to 6.2.6 in the meantime.  I've not had any issue with 6.2.6 after downgrading from 6.4.0.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Yea, already done after I posted. Figured I'd give that a try. I didn't have that issue before I upgraded from the 4 to 4s and don't really see why its an issue with the 4S. There really isn't any hardware changes that I can think of that would cause it. New hardware - the part cooling fan, wifi module, and nfc module. I have the WiFi turned off because I have the printer hardwired.

I was also having a lot of layer shifting going on. Originally I thought it was due to the y-axis belt being loose. I tightened it and the y-axis went away, at least for a few prints, but then I was getting x-axis shifts. I tightened that belt and then I got the y-axis shift again.

Then I remembered we had a problem like this on our Prusa XL 5 Tool at work that I run. The shifts were caused by some of the acceleration settings in the slicer... if they were above 3,000mm/s^2 they could result in random layer shifts. I lowered all those acceleration control settings to a max of 2,500 and the layer shifts disappeared. Hoping that will solve the issue here.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Same issue here, MK4S+MMU2S with stable FW 6.4.0. Downgraded to 6.2.6 and printed ok. It looked that one of the filaments was having issuing loading/unloading and FW 6.4.0 couldn't handle it, while 6.2.6 infomed me of the problem and assisted me in manually unloading/loading the filament... My guess, 6.4.0 cannot propperly handle some MMU filamente loading/unloading errors.

RE: MK4S +MMU3 + 6.40 Alpha FW - Stuck at Reloading Filament - 99% Parking

Same issue here. I switched from filament stations 1 and 2 to stations 3 and 4 and the problem went away.

Checking subsequent posts, it looks like it may be related to failure to properly report a problem loading filaments.

I may downgrade to firmware 6.2.6 to get avoid this in the future until this bug is fixed.

Specs:

Prusa MK4S Firmware 6.4.0+11974 supported

MMU version 3.0.3

PrusaSlicer 2.9.4