We have PHENOM XXL
When powered on the build plate descends rapidly (much faster than when moved by the motor).
It's like it is in free fall, because I hear no sound suggesting that any motor is moving the lead screw.
I suspect that the machine doesn't even know it's happening, and the only way to stop it is to let machine power on all of the way, open the manual movement dialog and press up. If you weren't paying attention or not quick enough I would assume it would crash into the vat full of resin and lcd screen, even though there is a proximity switch at the bottom of the column (I haven't attempted to find out if it would stop itself or not, but my bet is on NO).
Anybody have any experience with this or remedy? Thanks in advance.