Anet A8 won't print properly
because the extruder gear doesn't really push it. It doesn't seem like it's stuck, but it just won't move.


It looks like stepper issue.


Did you check stepper connections? Maybe there is a loose wire?
Maybe your extruder is assembled incorrectly? Please check google images to see how extruder should be assembled and/or give us some photos of your extruder.
Maybe your printer is setup wrong, there is small potentiometer on mainboard which sets stepper current, I had problems when it was rotated slightly too far. Try commanding your printer to extrude slowly for several seconds and in this time turn pot at least one time (it wraps around) until it starts to extrude (do not move printhead during this, turning this pot WILL make motors skip and crash into home/end). If you don't have problems with other motors, this may not be your issue but is worth checking.
Try homing your axes first, sometimes after startup motors won't work correctly until homing axes.
Try pressing reset once after starting printer.


How to find that pot? It's just to the side of capacitor which is near "Z-Motor2" connector.