Poor connection to Einsy  

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I would recommend you contact support via eChat on the shop.  

Re:

I've spoken to three different support reps. They each have me remove and replug the connectors. It works for a few prints before they work loose again. They peace out as soon as it starts working again. 

Contact them again

Posted by: @erik-3

I've spoken to three different support reps. They each have me remove and replug the connectors. It works for a few prints before they work loose again. They peace out as soon as it starts working again. 

Contact them again and tell them that has not worked the last dozen times you tired.  

RE: Poor connection to Einsy

Posted by: @erik-3

The connection inside the control box from the MMU2S to the Einsy in my MK3S will not stay connected. This results in my MMU2S crashing a LOT when trying to home. Instead of gently bumping the end of the axis to home the unit, it rams into it and just grinds the motor for up to 30 seconds. It will also sometimes error out when performing tool changes. If I open the Einsy's case and hold the MMU2S connection to the board it performs as expected. These cables are connected to the Einsy without plugs that fit. Instead, they're connected to some pins within a much larger connector. Is there a remedy for this that doesn't involve glue or crimping my own connectors?

Hello,

The best thing will probably be if you configure a suitable plug (sensor and MMU2), otherwise you will always have problems with it. The solution with the plastic insert is also not the best.

https://d17kynu4zpq5hy.cloudfront.net/igi/prusa3d/PEZDfN4mo3VcBCHp.medium

wbr,

Karl

RE: Poor connection to Einsy

Alright! Update time. I got the little spacer printed and inserted. I am still having MMU issues with it grinding the selector when trying to home. I have verified all connects are secure on the Einsy and MMU board. I removed the control board from the top of the MMU to hold the connectors while I home the MMU. No dice. Here is the grinding issue. Sometimes it works fine, sometimes it does this for upwards of 30 seconds.

Support did a little troubleshooting with another issue I'm having and we'll see how that turns out. That issue is that during an unload procedure the unit will stop and flash all 5 LEDs (insufficient power).

Could this be a problem with the cables going through the cut out that you had to make in the Einsy door? A damaged cable there will give you these same problems. Did you also check the crews had connect the power cables to the Einsy board?

I just had a quick look at the handbook to see what Prusa says about the 5 LEDS blinking. The MMU has to detect the low power 3 times before flashing all LEDs red and green. (all red = filament detected in the selector)

I have checked my MMU and when homing the selector it some times bumps the right homing position 3 or 4 times (1-2 seconds each time) That sounds like what the MK3 does when calibrating the z axis to the top of the z axis.

I'm pretty sure it hasn't always done this with that sound. It was more like when the MK3 homes the x and y axis. Just a bump, but not rattling that long. But my MMU does work without any problems.

I can imagine that the rattle when homing could be caused by insufficient power to the motor.

Does it make a difference if you use Normal or Stealth mode for the MMU? (in the Settings menu)

There are ribbon cable connectors that should fit the connector on the Einsy board. But you would have to solder the MMU and Filament sensor cable to that single connector. That would make it harder if you have to change something in the future.

RE: Poor connection to Einsy

I suspect there is a bad cable somewhere. When this print finishes I'll take the covers off of the wires and see if I can find a pinch or break in the jacket of a wire.

I took apart the MMU to check a few things and couldn't find anything other than a loose screw on the idler. The support rep suggested both of the screws need to be tightened evenly and not overly tight. I haven't had an unloading problem (low power) issue since, but it hasn't been long and the problem is intermittent. 

You are correct in your description of the sound being similar to the Z Axis calibration. It isn't a huge deal if it's just a quick rattle. It has been limited to 1-2 seconds like you describe since I reassembled the unit. I'll check the wiring anyway to be sure.

Normal and Stealth mode don't make any difference for the grinding. I haven't been able to reproduce the power issue since working with the rep. I have tried in both modes.

Suspect

Posted by: @erik-3

I suspect there is a bad cable somewhere. 

I suspect you are right.  

RE: Suspect

I removed all cables from the MMU and looked them over. I didn't see any jackets with breaks. I didn't see any crimps in any wires. I'm not sure what's going on. I tried to start a print just now and it flashed all 5 red/green LEDs again.