Homing problem on initial setup

[LarryM]

Here are the two relevant threads:

[Guide] Using Grbl to debug your homing switches

If you are having difficulties with your homing switches you can do a quick test with Grbl to see what the state of the homing switches is from Grbl’s point of view. NOTE: In order to use this procedure you need to have grbl Version 0.9j or later installed on your Arduino. To do so, you use the Grbl status immediate command ? (question mark). This command asks Grbl for its current value of some of its state information. For the purpose of this article we are interested in the homing switch stat…

Changes to the status report for Grbl version 1.0c

Updates to grbl have changed status reporting in version 1.0c (used in the X-controller I believe). These changes affect the output from the “?” status command to grbl. Information here is based on version 1.0c (edge fork). The status report mask (grbl parameter $10) has two new control bits to select display of the probe pin and control pins’ status. The bit assignments are as follows: 7 - Not used at this time 6 - display control pin status 5 - display probe pin status 4 - display homin…