I did it - Upgraded MK2.5S to MK3 - A Axis Length Error
After starting with an MK2, later upgrading to MK2.5S, I finally had enough with noisy steppers and just decided to upgrade to MK3. Well, I upgraded everything but the frame. new Einsy Rambo, new 24v PowerSupply, 24v HeatBed & Heatbed Frame, New Hot-End (unnecessarily?), New PINDA, New Noctua Fans...
Flashed with 3.11 Firmware for MK3.
But I'm getting an error: Self Test Error Axis Length X
The frame is square, no racking. Gantry slides freely in X and Y. I'm not sure what would be causing this so I come here hoping someone might point me in the right direction.
RE: I did it - Upgraded MK2.5S to MK3 - A Axis Length Error
you have probably read this: https://help.prusa3d.com/article/check-axis-length-x-y-z-mk3s_134223
Besides that it might be the X-axis endstopper.
I have a MK2.5S and to pass selftest I have glued a cube of 5 x 5 x 5 mm to the X-carriage so it hits the stopperswitch earlier.
Maybe you have to check/change simular
We will do what we have always done. We will find hope in the impossible.