I have been working on this machine for the last 8 months to trying to get this machine from a pretty beat up "players condition" to something resembling a real playable, working game. After getting the bookcase, thing hand, swamp kickout, and thing flips working, things looked like they were looking up.
Until I found that the three swamp lock switches stopped working, ok, so no big deal, take some pictures of the switches, pull them all, a little solder here and put them back. Now a ball will not lock for multiball. Tested the switches with a ball in switch edge, and all switches register as working. The only thing I can guss is I have the switches in the wrong order.
So now with the history out of the way, does anyone know what the correct order the switches are supposed to close for lock? Should the first lock be lower swamp lock, then center, then upper? Since this is a physical lock the order of the switches should matter, so the game will recognize that a ball has indeed been locked and needs to drop a new ball into the shooter lane, I think...
Anyway thanks for reading, and any help you can offer.

Does it flip with a flipper button? If not, check the coil to make sure its getting power. Do your bookcase optos work? If not check to make sure you have all your 12 volts from the power driver board.
If everything is fine make sure that you wired the optos you replaced correctly, check for solder forming a bridge between the solder pads (god knows I've done that a few times).
Good luck.

Thanks dmklunk, and terryb. It was a combination of not having the switches in the right order, the whole swamp assembly being slightly misaligned, and the lower lock switch had one of those spacers that was too tall and was causing the switch wire form from fully closing the switch.
You both are scholars and gentlemen....
Now its SHOWTIME!!!!