X-Axis Endstop not working??

Hey guys. So I just built my first Prusa i3. Everything is working except for the X-Axis endstop. The physical switch itself works when I plug it into the Y or Z endstop pins on the RAMPS board for testing. The other switches do not work on the X-Axis pins on the RAMPS board though. So my first thought (an obvious wrong one) was that the RAMPS board or MEGA had a bad I/O pin. I swapped both out and the same issue persists. So it's obviously a software issue. I did try a fresh Marlin firmware, but no change. I'm asking for one of your ultra-reprap-wizards to give me any clue as to maybe what section of the firmware code to check to confirm that endstop is being recognized. This issue has been going on for over 1 month while I waited for replacement parts to come in to try and fix it. I'd just like to be able to use the printer....

Any help would be greatly appreciated!!

Thanks in advance,
Mike


UPDATE: 6/12/15: So I was messing around with a variety of the X-Axis Inverter/Endstop settings. It works when I have the endstop home set to '1', but not '-1'. Shouldn't home be the left front corner of the bed?

Edited 1 time(s). Last edit at 06/12/2015 09:20PM by mrmills129.

The endstop direction (1 vs -1) has to match both the physical location of your endstop and the location on the RAMPS that you plug it into. Sounds like you have it plugged into the XMAX position. If the endstop is on the left as you look at the printer from the front, then you need to swap it over to XMIN and set the direction back to -1. If that doesn't seem to fit your situation, perhaps you could take a couple of photos to show the location of your endstop and the pins it is connected to.

And welcome to the forum!

Wow... thanks James! That solved it. I didn't realize there were I/O pins for XMAX & XMIN. Setting the firmware up and those pins on MAX is great. This is a great place for learning... I LOVE IT!!!