New MMU2S DOA?
I have had my MK3S for a few months now and no problems with it. Prints beautifully. I recently received my MMU2S upgrade which I assembled over the weekend. No real problems putting it together (I put the MK3S together from the kit). When doing the pre-flight checks and getting ready to flash the firmware, the MMU2S doesn't seem to be powering up. No lights, or sounds, and plugging it into USB on the PC doesn't show anything connected. The MK3S is powered up fine. I tried the following:
Continuity test on the power cable from the MK3S to the MMU2S thinking its not getting power - passed no problems
Check power at the Einsy board - checks out 24V
Check power at the end of the power cable to the MMU2S - checks out seeing 24V there too
I've gone back through the instructions and I didn't miss anything that I saw. Wiring looks fine too. Have I missed something here or is there just something wrong with the MMU2S board? I've sent an e-mail to info@prusa (2 actually) over a day ago about this but I haven't got any response yet. Just want to make sure I didn't miss something stupid.
Thanks in advance.
RE: New MMU2S DOA?
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RE: New MMU2S DOA?
The power cable is hard to mess up, so with the printer turned on, check the FINDA to see if it is lit (may have to cup your hand around it as it is much dimmer than the PINDA). If it is then you know the board is at least getting/distributing power.
The next thing is to double check that the other cable is plugged in the correct slot on the Einsy, but if your IR sensor is working correctly then there really isn't any other option.
At that point if the printer isn't seeing it and it doesn't light up, then more likely than not you have a bad board. I think you'd make the 3rd or 4th example of that I've seen in the last month or so. @nikolai-r is correct, use the live support (have to be logged into the store to see it) and they'll get you a new board in a few days.
RE: New MMU2S DOA?
I had the same description. I went so far as to trace solder point to solder point (with the printer off) on the comm cable on the backsides of the boards to eliminate the comm cable as a problem.
The only thing I got was that if you turn the printer ON with the comm cable disconnected and THEN connect the comm cable, all 10 LEDs on the MMU2S board illuminate and stay illuminated. This does not impact it's ability to connect via USB or anything else however, but it's... a thing I guess. I have tried with all motors disconnected and also to no avail.
I was sent a replacement MMU2S board, no improvement, so they had me send the MMU2S board back along with my EINSY board. I got the replacement EINSY board and plugged it back in with the MMU2S board and still no dice. Still awaiting a response on what to try next.
I think Prusa is overwhelmed right now, as I've heard conflicting troubleshooting from their team.
-One said you can't get USB working unless the MMU2S has power and comms.
-One said you can get USB working with power only.
-One said you can get USB to detect without even power, but can't flash.
In theory at this point my EINSY board was always fine and I got a bad MMU2S board AND the replacement was also bad. That or there's something else Prusa is struggling with.