Hi all, new to ZeePro here. 
Trying to get it to print something for the first time.
After a few hours of firmware, driver update and diagosis.
All leads points to the Z-axis stepper motor malfunctioning…
so the motor seems to gets very unhappy at any speed faster than 3mm/s.
Check it out. 
(It makes loud humming noise and a weird hump, and but doesn’t want to move, However when I try to run it at 3mm/s it seems to be doing okay.)
I took the Zim apart further more, the shaft doesn’t seem to have much resistant.
Ladies and Gentlemen thank you for your time, some pointers are highly appreciated!