MMU2s Grinding after upgrade to 3.13.0 - Hardware, firmware and software help

RE: MMU2s Grinding after upgrade to 3.13.0

Inglemation — Tue, 14 Nov 2023 23:54:57 +0000

Wow. Prusa still feeding their customers the same old line about the MMU's power issues being due to improperly secured wires. The MMU power issues have been thoroughly investigated by the community. The vast majority of power issues arise from a cheap diode on the board that, over time, reduces the 5V+ voltage to below the working threshold of the stepper motor drivers. Even if this particular issue isn't due to the cheap diode, it's irresponsible of the support team to not mention it. There are several massive forums devoted to this issue. Here's the one I found to be most helpful:

https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/i-found-serious-design-error-in-mmu2-electronics-hardware/paged/4/

RE:

Inglemation — Tue, 14 Nov 2023 23:43:13 +0000

I would like more clarification on this as well. When you go to Prusa's downloads page for the MMU2S, the file that is downloaded is labeled MMU3. I searched around, and the only information I found on this was on a GitHub page where an apparent Prusa dev says that the MMU3 firmware is supposed to work on the MMU2S. It absolutely blows my mind that they can't make anything user-friendly. They expect all of their users to be programmers or something. If I was a good programmer, I would have bought an Ender 3. There is no reason that I should have to search Google and look through 4 or 5 results just to find a GitHub page that tells me what I'm doing MIGHT be right. Why don't they just put something on the Prusa downloads website page that says "The file you download will be labeled MMU3, but rest assured this firmware is compatible with the MMU2S as long as you have firmware version XXXXX on your MK3S printer or firmware version XXXXX on your MK2 printer, etc." WHY IS EVERYTHING SO ********* HARD THESE DAYS WITH PRUSA?!?! They're starting to REALLY make me mad lately. It feels like a totally different company than the one I bought my first printer from 2 years ago. Also, the "How to" PDF's on the MMU3 firmware download are all for printers and not for the MMU unit. And the README has no helpful info except yet another link to another GitHub page. It's freaking absurd. I feel bad for anybody who is a beginner and was told to buy a Prusa because they're so user-friendly.

RE:

Narimus — Wed, 04 Oct 2023 04:05:46 +0000

I had the same problem with the 3.13.0+ firmware. However, looking at the file I'm flashing it to the MMU2 is MMU3 in the filename. Further when I tried to print it told me I sliced for a different printer. Looks like the problem could be that we are flashing MMU3 firmware to MMU2 assemblies. I hope I didn't break anything doing this.

RE: MMU2s Grinding after upgrade to 3.13.0

MikiCab — Sun, 01 Oct 2023 01:43:45 +0000

Here is the response from Prusa Support.

I will look over these suggestions and see if they fix anything but they didn't address the fact that the system runs fine with 3.12.2 and does not run at all with 3.13.1. I am hesitant to brick my system again by attempting the FW upgrade a second time.

From Prusa Support: Hope it helps anyone who is having a similar issue.

"Dear Richard, Thank you for providing the video.The idler homing issues with the new firmware can be caused by the MMU not getting enough power which can be caused by the power and signal cables not being connected securely enough. You can check the cables with a multimeter as mentioned at https://help.prusa3d.com/article/multimeter-usage_2117 and make sure that the idler can move smoothly per https://help.prusa3d.com/guide/5-pulley-body-assembly_43152#44160. The MMU smooth rods must be clean and lubricated and the brass tubes must be secured tightly inside the selector body. Our developers are also working on the next firmware version that should fix some of the reported issues. Please let me know if there is anything else I can help you with. Have a great day.Best regards,"

RE: MMU2s Grinding after upgrade to 3.13.0

gudnimg — Sun, 24 Sep 2023 21:18:26 +0000

No problem 🙂 If you have trouble next time around feel free to ping me here and I’ll help if I can.

RE: MMU2s Grinding after upgrade to 3.13.0

MikiCab — Sun, 24 Sep 2023 21:10:23 +0000

Thanks. I was in settings and didn't see it. When I reload the FW I will check again. I have downgraded to 3.12.2 so I can get some prints done so I cannot do anything for about a week. I cannot risk bricking my system again.

RE: MMU2s Grinding after upgrade to 3.13.0

gudnimg — Sun, 24 Sep 2023 21:05:28 +0000

It should be under “Settings”. See attached image.

0e006589-img_3933.jpeg

RE:

MikiCab — Sun, 24 Sep 2023 21:03:56 +0000

I went through the menu and could not enable the MMU2s. Which menu option do you enable it through? I went through Settings, Calibrate, Support and was scrolling through. I can't say I went through with a fine tooth comb but I didn't notice any MMU2s enable or Disable option. I could see it was Disabled in one of the menus.

RE: MMU2s Grinding after upgrade to 3.13.0

gudnimg — Sun, 24 Sep 2023 21:00:59 +0000

A common problem is people haven’t enabled the MMU in the LCD Settings menu. This is a new setting so the MMU can be disabled anytime, by default the MMU is disabled.

RE: MMU2s Grinding after upgrade to 3.13.0

MikiCab — Thu, 21 Sep 2023 15:50:47 +0000

I unbricked my system by rolling the FW back to the last version 3.12.2. None of the fixes I found online worked. I will wait a month of so before I try this again.