Failing calibration
Hey, I bought the Prusa i3 MK3S+ (already assembled) an year ago and I have been printing without any issues until now. However, lately my son played around with the printer moving the bed forward and backwards. Since then the printer started making a rattling noise when the bed goes towards the end position at the back and the prints come out distorted - you can see that the layers keep shifting around and the print is unusable.
I tried performing the self-checks and the XYZ calibration. Self-checks are always OK, but the XYZ calibration fails after the 4th point with the message "XYZ calibration failed. Please consult the manual". I tried a full system reset and flashing the latest firmware, but this didn't help - the calibration keeps failing. The belt seem OK and th ebed moves smoothly.
I'm sure the printer was assembled correctly initially and it was printing fine all this time. Any advice where I can search for the problem and what to try? Thanks!