If you start moving your table up or down, and it abruptly goes to the bottom, you may need this procedure. The most common cause of this problem is that the home sensor is dirty.
Turn on the machine, and wait for READY on the laser control panel. Press Escape and get the first menu.
Move the cursor down to the left of PREFERENCES, and press SELECT.
Go to CONFIGURATION and press SELECT
At the same time, pres the SELECT and the DOWN SCROLL arrow (bottom arrow next to escape). This will bring up a hidden menu Z-AXIS OVERRIDE.
Press SELECT on the Z-AXIS override to turn it on.
Press ESCAPE three times to get to the display shown to left. Move the cursor next to FILE DISPLAY and press SELECT.
This will get you back to FILE DISPLAY or JOB screen.
Press the XY Button. .Move the cursor down to RE-HOME X-Y and press Select. Wait for the motion system to re-home.
Press ESCAPE and press the Z button. You should now be able to adjust the Z-axis up and down (arrows next to SELECT and ESCAPE.
Note: if this doesn’t work, you will need to replace Z-AXIS limit switch assembly
After moving you Z-axis to the normal position, you will need to turn the override off. Follow the steps beginning steps above, and turn off the Z Override.