If your Z Endstop is not triggering this could be due to a manufacturer wiring configuration on your Z endstop connector. The EZABL board has been set up based on testing of multiple machines that we have in house. But after sending out many kits it appears that the wiring that manufacturers use are not consistent and they reversed the wires in some Z Endstop connectors. This information is also covered in the EZABL kit installation guide.
EZABL Pro Kits
Just flip the Z endstop switch on the EZABL Pro Board to reverse the wiring. No swapping pins is needed on the EZABL Pro kits.
Older EZABL Kits (V1-3.1)
Direct Wire - Swap the 2 wires going to the Z endstop screw terminal
EZ-Connect - Use a small pin to carefully push out the wires from the Z Endstop pin and swap them around. This will make the Z Endstop trigger.
Once you change the switch position (EZABL Pro) or the wiring re-run the M119 test. It should look like the screenshot below:
When the LEDs on the sensor and EZABL board are off z_min should show open. When the LEDs on the sensor and EZABL board are on z_min should show TRIGGERED.
Swapping JST pin wires (for older EZ-Connect EZABL Kits V1-3.1)
Here is a video showing how to do this. The connector in the video is slightly different than the Z Endstop plugs used on the printers but this method works the same.
But why do I need to do this when the stock Z switch works?
The EZABL module uses an IC chip that is what is similar to a diode. Diodes only allow electricity to flow one direction. Whereas a switch just connects 2 wires together no matter what way they are connected. If the wires are reversed from the baseline printers that we used for testing then the signal will not flow and reversing the wires will fix this.
Will my stock Z Endstop still work if I want to go back to it?
Yes, this will not change how the stock switch works and you will not need to swap the wires back before installing the stock Z endstop switch.