2 out of 10 Prusa printers won't connect to OctoPrint via serial port


I have currently 10 Prusa printers (and growing) in my 3D printing farm, 7 are MK3 and 3 are MK3S.

One Prusa MK3 and one Prusa MK3S just won't connect to Raspberry Pi over serial port. I use same Raspberry Pi and same usb cable to connect to other 8 printer without problems.

Also boards and serial port on both "problematic" Prusa machines works ok when I connect to a laptop. I tried updating firmware to both "problematic" printers via two different laptops, one running Linux and other Windows, and this works without problem.

I can't figure out why these two have problems connecting to Raspberry Pi over serial, any ideas?

Does Prusa have different usb to serial chips on different boards? What could cause this?


A few minutes later I found this post:

Changed RPI Port to off on first printer and now it connects, will try on second one as soon as it finishes current print job.

Just to clarify: In German language we differ two states of same:

  1. "das Selbe" - that means this one item.
  2. "das Gleiche" - an 100% identical 2nd item.

So you have troubles to connect with the same equipment as stated in 1. or in 2.?

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But if you see my second post the issue is resolved.

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I just saw your 2nd post when I hit the send button...

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