RE: Layer shift?
You could check the belt tension and if the setscrews for the pinions driving the belts are tightened enough. Which direction is the shift? x or y?
RE: Layer shift?
Shift was in X. That was first attempt at printing PETG (Prusament Carmine RED). I tried another small print and it did something similar... it actually kept pulling the extruder head away and flashing "collision detected"... there was a little booger of plastic sticking above the layer it was printing, kinda looked like a little furball that got rolled up. Maybe it was bumping that and triggering the collision warning, but it had layer shifted as well so just canceled the print.
I checked the belt tension and the pulley on the stepper and can't detect any play (held the flat spot on the motor shaft with pliers and tried to move the extruder head like the kit instructions said). So switched back to PLA and printed a couple of things for a little test and got perfect prints.
I read about PETG absorbing moisture, so threw the roll of filament into the dehydrator and let it cook. Will try it again in a day or so.
RE: Layer shift?
Yes, PETG prints better after drying.