Output Switch Troubleshooting

Hi folks,

I mistakenly connected the wrong wire to the ground terminal on the Input Switch block (I'm a bit colour-blind, alas). Since then the Output Switches have stopped working, though the Input Switches are fine. The Output Switch indicators on the computer show they're activated but there's no change in the voltage between any Output Switch terminal and the ground terminal whether the switch is activated or not. I have a friend well accustomed to working with electronics but I'd like to give him as much help as possible. The excellent folks at ShopBot, unfortunately, don't have any drawings of this particular circuit board (V 0.6). Do any of you who are more electronically skilled have any drawings of this board or this area of this board and/or do you have any suggestions on parts to check first? There's 24V at the Output Switch block and the ground terminal is also fine.