Filament Loading and Z-axis issue  

Filament Loading and Z-axis issue

I bought a semi-assembled Mini+ and put it together yesterday and today.  I bought the filament sensor and added that as well although I had trouble inserting the PETG tube from the machine.  Everything tested well on the selftest.  I tried to load the PLA filament and the drive made a chattering noise.  I tried a couple more times and the same thing happened.  I turned the machine off and back on.  With the filament removed, I started to try and load the filament again, only it said the filament was already loaded.  I still tried to load the filament again and still had no luck.  (Yes I cut an angle on the filament).  I then decided to removed the filament sensor to simplify things.  I wanted to try to remove the cable from the Mini+ computer.  To get easier access, I tried to move the z-axis by hand, only I couldn't do it.  I could move the x and y axis but not the z.

Any ideas?