Fixing 3D Printing Problems

(1) Extruder Head / Extrusion Problems
 
(1.1) Printer does not extrude plastic (Clogs)
 
(1.2) The filament broke off, how do I remove it?
 
(1.3) The first layer looks wavy
 
(1.4) The nozzle scratches the turntable
 
(2) Other Hardware Problems
 
(2.1) The turntable and the 3-pin adapter fell apart
 
(3) Slicing Problems
 
(3.1) Please send us your question!