If you have 12v on one side and don't have 5v on the other, there are only a few things that can cause this.
1. Bad 7805
2. Got one of the mosfets by mistake - if they get mixed together it's hard to tell them apart.
3. Short on the board.
4. 7805 in backwards?
Since this is easy, I'd remove the three chips and see if you still have 0v - one of them could be bad and shorting out the board. I didn't see any solder bridges.
Next, I'd bite the bullet and try to remove the 7805. It's not going to easy though and you are going to need either a really good solder sucker or solder wick... I'd start with just the heatsink first...
RM