My vertex worked perfectly for over a year, but then all of a sudden there was no (or very little) filament coming out of the print head. I took everything apart, cleaned the nozzle, made everything smooth again. After reassembling I loaded the filament which seemed to come out like it should (although it might have been a bit less then usual). But still when I started a gcode that worked well before, there was very little or no filament coming out.
If you cleaned your nozzle and hence are sure it’s not blocked, it might be the mechanism that is pushing the filament, one thing that comes to mind is the pulley that sits on the axis of the stepper motor that pushes the filament. It can work it self loose over time - did you check if it is tightly attached to the axis of the stepper motor?
It that is tight, try holding the filament lightly with your fingers when the printer is printing, do you feel or hear anything, like if it tries to pull the filament but it is slipping?
