I found serious design error in MMU2 electronics hardware  

RE: I found serious design error in MMU2 electronics hardware

Thanks for the Info. I've tried to contact the live chat yesterday, but quit the chat after an hour... although the waiting time was estimated with 11 minutes 😅
I'll try again today 🙂

RE: I found serious design error in MMU2 electronics hardware

"free upgrade"? just the voltage do-dad or the whole MMU3?

RE: I found serious design error in MMU2 electronics hardware

At the moment, I'm waiting for response from the support team.

The blog-post mentions: 

So, if you have contacted our tech support in the past and you didn’t manage to get the MMU2S unit fully up and running without issues: please try installing the new firmware first. I’m pretty sure it can do a lot to make the MMU2S better. And if the new firmware won’t help, get in touch with our support team to consult your case and troubleshoot the issue. If a solution still cannot be found, we are ready to send you a free voucher for the MMU2S->MMU3 upgrade kit (available in about 4 weeks). We’re keeping this opportunity open till the end of this year.

This is inconsistent to the 30% voucher, I was offered today in the prusa support chart.
I've mentioned this in a mail to them and waiting now for a response.

In my case, the problem is related to the power cable.
Seperating power- and data-cable (the two from the mk3-board to the mmu) should improve things.
On my side, i could reproduce the failing behavior, by bringing them close together again.

Look here: https://www.youtube.com/shorts/cO3cWX2r0r0  

RE: I found serious design error in MMU2 electronics hardware

Curious about the free replacement - Has anyone confirmed this issue is covered? The blog post could be read to say if you never got it working, rather than it was working fine, and then stopped. Sounds like most of us in this thread are in the "it worked, then it didn't" camp. When I spoke to support before this post came out, they were only willing to send new MMU2 boards to those under warranty, and I was no longer under warranty.

RE: I found serious design error in MMU2 electronics hardware

Chatting with support right now, haven't gotten anywhere yet.

RE: I found serious design error in MMU2 electronics hardware

Posted by: @realityfoundry

Chatting with support right now, haven't gotten anywhere yet.

Im finding the post now so you can show them and request it

RE: I found serious design error in MMU2 electronics hardware

https://blog.prusa3d.com/original-prusa-mmu3-is-here-multi-material-printing-with-improvements-all-around-now-shipping_80485/

RE: I found serious design error in MMU2 electronics hardware

RE: I found serious design error in MMU2 electronics hardware

That's the post, I showed it to them, brought up this thread, identified all the issues, they initially hit me with a "30% off upgrade" voucher, and I pointed out specifically the "Free upgrade path through the end of the year" post, they passed me on to someone else, then said they'd have to get back to me after taking my email.. I'll post back here when I hear something, although I am still going to attempt the diode bypass as I need my MMU's working asap..

RE: I found serious design error in MMU2 electronics hardware

Just of curiosity: Did separating the two wires-bundles help on your machine?

RE: I found serious design error in MMU2 electronics hardware

The „if you have contacted our tech support in the past and you didn't manage to get the MMU2S unit fully up and running without issues“ part is doing the heavy lifting in that post. 
So to qualify for that free upgrade you not only have to have contacted the support in the past because of problems with your MMU2, you additional need to be on record for not solving your problems… having a MMU2 which started to show problems some time down the road, after working for some time will probably not suffice. 

RE: I found serious design error in MMU2 electronics hardware

yeah leaving themselves an out...    Even though mine mostly works and it works better with the latest firmware, I think I'll probably ditch mine when my MK4 upgrades finally arrive.   I've definitely had the exact issue this whole issue describes with the all 5 lights blinking both green and orange which the manual says is  "power issue".  Since the mmu3 still really won't solve tpu or mixing filaments with vastly different printing temperatures, it's nothing more than a curiosity for me.   It's why I have the 5 extruder XL coming(at some point).  

Posted by: @robin

The „if you have contacted our tech support in the past and you didn't manage to get the MMU2S unit fully up and running without issues“ part is doing the heavy lifting in that post. 
So to qualify for that free upgrade you not only have to have contacted the support in the past because of problems with your MMU2, you additional need to be on record for not solving your problems… having a MMU2 which started to show problems some time down the road, after working for some time will probably not suffice. 

RE: I found serious design error in MMU2 electronics hardware

Of course, it's in their hand, if they offer us a working free upgrade or not.

From a moral standpoint, they should offer at least every customer the PD-Component for free.
I mean, they sold an item, later knowing that they did something wrong (voltage too low) - and we, the customers already paid full price.

The PD-Component should not be that expensive. I know, I know... the logistics about that item is.

But they are a company - with all the benefits AND drawbacks, being a company comes with.

I don't want to sound greedy now, but at the moment I personally feel a little betrayed. 
I've spent a ton of time in getting the MMU running - or better said "stable" running.

Not having contacted prusa directly, but reading forums, watching videos, etc. to get it fixed, shouldn't be punished.. 😐

RE: I found serious design error in MMU2 electronics hardware

Sorry for the bad video, this was my first time making one. This should help everyone with the wiring and soldering questions.

VIDEO LINK

Prusa MMU2s power issues fix, injecting 5.2v

Prusa MMU2s power issues fix, injecting 5.2v

RE: I found serious design error in MMU2 electronics hardware

Hello Group! I am read and re-read this thread and one thing I can figure out is the recommended installation steps to add the step LM2596 to the PCB. If anyone can please take a few minutes to exactly describe what I need to do and if you are able to take photos, I would be forever grateful. I have upgraded the firmware to the latest 3.o version and ever since I am being plagued with MCU errors. I know there is a fix in this thread but I can figure out exactly how to do it. TIA.

RE: I found serious design error in MMU2 electronics hardware

I made a video how to install it

its the post before yours 

RE: I found serious design error in MMU2 electronics hardware

I've got an update from Prusa Support, which states the the power is actually the problem (which the PD solves).
Also they say clearly, that the free MMU3-Upgrade is only for users, who contacted support in the past. It seem's I'm a few weeks to late..

I am sorry that the issue persists. A PD board would be a solution to your issue. Unfortunately, we are not able to provide it separately. It doesn't fit in the old MMU plastics. It is bent, and we are not exactly sure what the consequences could be .Furthermore, I have seen no record of you contacting us to troubleshoot the MMU. As a result, I would like to offer you a 30% discount for the MMU3 upgrade, as I highly believe it will solve all of your current issues. 

Anyway.
Meanwhile I've printed all MMU3 parts and upgraded by myself 🙂
I had everything I needed, expect the 5mm coupler. I've used this remix of the idler, which works as far great for me:
https://www.printables.com/model/564378-mmu3-idler-mod

The only thing I'm now missing is the PD board ... or a bulky custom LM2596 solution (which is much cheaper).

Maybe I'm lucky and they offer the PD board as a spare part later this year  🙃 

RE: I found serious design error in MMU2 electronics hardware

Posted by: @sensenmann

I've got an update from Prusa Support, which states the the power is actually the problem (which the PD solves).
Also they say clearly, that the free MMU3-Upgrade is only for users, who contacted support in the past. It seem's I'm a few weeks to late..

I am sorry that the issue persists. A PD board would be a solution to your issue. Unfortunately, we are not able to provide it separately. It doesn't fit in the old MMU plastics. It is bent, and we are not exactly sure what the consequences could be .Furthermore, I have seen no record of you contacting us to troubleshoot the MMU. As a result, I would like to offer you a 30% discount for the MMU3 upgrade, as I highly believe it will solve all of your current issues. 

Anyway.
Meanwhile I've printed all MMU3 parts and upgraded by myself 🙂
I had everything I needed, expect the 5mm coupler. I've used this remix of the idler, which works as far great for me:
https://www.printables.com/model/564378-mmu3-idler-mod

The only thing I'm now missing is the PD board ... or a bulky custom LM2596 solution (which is much cheaper).

Maybe I'm lucky and they offer the PD board as a spare part later this year  🙃 

Wait, what’s new in the new mmu3? 
As in the bill of materials

can we just “upgrade” by transferring our parts to the new one except the idler? (Which you solved by using 16 teeth pulleys?)

becauee I’ll also be interested in doing that. I printed a case for my LM2596. Less ugly looking and mounted it to the top of that MMU2s 

RE: I found serious design error in MMU2 electronics hardware

Just been talking to support who confirmed they will only offer the upgrade voucher under a 1 yr warranty with a photo of the error message (see attached) and the original order number. Out of warranty you need to buy the upgrade. They did say there was a discount they could offer on units older than a year, but I suspect that just to be compliant with the EU faulty good directive and similar consumer protection laws.  Overall the 'free voucher' is nothing more than the minimum to that Prusa are legally required to do under EU law wrapped in cynical marketing. They continue to refuse to acknowledge this issue as a design fault even though it is abundantly clear it is an issue as evidenced by the voltage boost board add-on in the MMU3. Very disappointed in Prusa, not a customer friendly company at all. From what I read Bambu has much better customer service (and product).

RE: I found serious design error in MMU2 electronics hardware

Posted by: @drsp123

Just been talking to support who confirmed they will only offer the upgrade voucher under a 1 yr warranty with a photo of the error message (see attached) and the original order number. Out of warranty you need to buy the upgrade. They did say there was a discount they could offer on units older than a year, but I suspect that just to be compliant with the EU faulty good directive and similar consumer protection laws.  Overall the 'free voucher' is nothing more than the minimum to that Prusa are legally required to do under EU law wrapped in cynical marketing. They continue to refuse to acknowledge this issue as a design fault even though it is abundantly clear it is an issue as evidenced by the voltage boost board add-on in the MMU3. Very disappointed in Prusa, not a customer friendly company at all. From what I read Bambu has much better customer service (and product).

I'm personally pretty much done with prusa products. I am very disappointed that prusa never properly fixed the MMU2 stability issues themselves, but decided to ignore the whole problem until they could release a following product. This is not a product support I expect from prusa.

I have to also mention that I am also disappointed with the recent changes what comes to MK3 -> MK3.x/MK4 upgrades. I happen to have an early MK3/MK3S+ with a silver power supply and soldered heatbead and this now adds +110€ to any existing upgrade price ---> it obviously doesn't make any financial sense to upgrade my MK3S+ with the current prices.

It looks like I will therefore continue with my Voron V2.4 and any upcoming core-xy designs, instead of pouring any money to my old bed-slinger printer. It's kind of shame, as the MK3S+ has been otherwise a pretty good work horse, but especially the easier calibration & maintenance would have been quite welcome features in my case.

I will just upgrade my MMU2S to the latest MMU3 just to get the updated stability improvements and especially to get rid of having to quess what these dreaded flashing led's are trying to indicate each time.