Layer shifting back and forth like a random offset in Y axis, no loose belt
My printer has some problems with layer shifting. Sometimes it is working fine for several layers but then it starts shifting in the Y direction up to 3mm. The shift is very random but it always stays withing a certain corridor. So if it shifts into one direction and then back to the correct zero position later.
I alredy checked a few things:
-updated to the latest firmware and software
-checked the belt tension. I also tried to move the bed while the printer is running and there is no way to shift the position by hand
-the stepper motor does not get hot
-the bed can move without any problems and I am not hitting the print while it is running
-the shifting can also happen right at the beginning so I do not think the board is overheating
This issue appeared when I used the printer after a long break and the first print failed (most likely due to a damaged nozzle) a lot of filament was sticking on the extruder. The nozzle has been replaced and extrusion is working fine. I also have no idea how that could impact the Y Motor below the heatbed.
Any ideas what could cause this issue?