New machine won't print

[mrjayd]

I assume then that when pressing the "Home" button, with the lock screws loosened, the trolley drops to a point and stops. If it does then the only possible problem is maladjustment of the platen. Try it again and press just very lightly on the platen when tightening the lock screws (front one first). Do not over-tighten the lock screws as that will cause the platen to shift position.

After manual alignment raise the platen by 0.1 mm and press the "Z=0" button. This sets a "logical" zero position at the current height when you press the button. G-Code printing commands for the platen to move to position "0" will move to this logical manually set "Z=0" position. The "Home" button will always move the platen to the hardware optical sensor controlled limit regardless of how the "Z=0" function is set.

A thought--what happens if you perform the alignment procedure, leave the paper (2 layers) in place, then  raise the platen 25 to 50 mm or so, and press the "Home" button once more? The platen should fall to where the paper is snug again, with no incident. If not I would begin to suspect an inconsistent or fouled optical sensor, or that the sensor "flag" on the bottom of the trolley is loose or fouled. Or that the trolley is set too tight on the rails and binding--when I disassembled my Mars to install the new mast i found it took 4.5 to 5.0 lbf to move the trolley--far too much I was able to adjust it to just 3 to 4 ounces. The Jackson mast requires zero force to move the trolley.

Z-axis sensor flag:

I also tried what you asked and went ahead and leveled again and raised it 50mm and hit home. It came all the way back down tight to the bottom and just starting humming again. No matter what I do it does this same thing every time.