Are you sure that MACH sees your limit switches? Have you set up the ports and pins for them correctly?
To check if your switches actually work, trip the switch manually. MACH should go to emergency mode (red EStop flashing) and tell you that you tripped the limit switch. You can also check the Diagnostics screen and see if your breakout board sends the correct signals to LPT port when you trip the switch.
After that you can set up your limit switches for homing. Sorry, I'm not at the CNC computer right now, can't guide you through the MACH settings. Hope this helps.
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