Quote Originally Posted by printbus View Post
If you have the endstop connectors where Colin shows them, and the mins work OK, maybe the right answer is to not worry about the maxs. configuration.h as the #defines for the pullups on the input pins for the max endstops commented out; this likely prevents the internal pullup being activated for those pins on the MEGA2560 processor. That would lead to the input being randomly read in as high or low. With the #defines for the max inputs commented out, firmware likely doesn't do anything with the inputs for the max switches. Your soldering is likely fine, since the min and max endstop switches would be on separate connectors on the RAMPS board.

I prefer the four springs approach. It allows me just get the Z endstop anywhere close, and then all fine adjustments are done in the four corners of the bed. Of course, I have thumbwheels on the corners now too. Leveling the bed takes me about two or three minutes. The stock makerfarm approach can easily take 20-30 minutes because of the complexity caused by the fixed corner and the multitude of tools required to adjust the other corners.
Trying to remember all your changes, did you print those thumb wheels out?