Mini-Rambo issue, steppers vibrates and takes extra steps

Hi Guys,

I have searched some but I could not really find any posts with similar issue.

A friend of mine in Sweden got this board

He flashed it with the firmware from V1’s Github

(My MPCNC has Ramps so Im not familiar with Rambo) and he shared that the steppers vibrates and take extra steps now and then. Same with all 4 steppers and on all channels. He tried the steppers in his Prusa printer and they works just fine.

He sent me 2 videos, one with 0.1mm steps only and another where he tries both 0.1 and 10mm.

Any suggestions for him how to troubleshoot the problem?



If that is the Chinese counterfeit version (no serial number on back) that’s making the rounds these days, the stepper wiring on them is wrong. You’ll have to do some debug to figure out how they are supposed to be wired and then just redo the harness.

Or the drivers are different, something. There is another thread on here with an import mini-rambo. I think he got his working.

Thanks Ryan and Bill, I’ll let him know.

Attached is a picture of his board, hard to tell but the white square in the bottom left corner is empty on his board but on repraps wiki it seems like there is a barcode there. I guess a clone then?

I’ll search the forum some more for “clone Mini-Rambo”. If someone happen to know a thread with a solution, please let me know.