I've been building a mendel for sometime now, finally I scraped together the last bit of money and got all my parts. I've finished pretty much all of the mechanical and electronic construction. I decided to test the axes out and discovered that they will only move forward, when I click the button to move the other direction (both in the reprap software and in repsnapper) they don't move. The lights light up for a split second on the controller but then nothing. I can't figure it out, I've switched the wires around into all possible positions, I think, I've searched the forum and google trying to find someone else who's had this issue. I don't know what the deal is any help would be greatly appreciated.
Thanks