Thanks for the reply.  I ran the switch test as you suggested.  I don't really notice anything happening and the display just shows "0".  I'm not sure if it's supposed to scroll through switch numbers or anything, but from what I can gather, if it shows "0" that should mean there are no stuck switches?  I thought about a diode on the solenoid too, but I don't have another solenoid or diodes to replace this one right now.  I did try grounding out the solenoid and it does fire when I do that.  Would that rule out the diodes at all?  I do have a solenoid from my Stern Meteor machine that is for flippers.  I guess I could solder it in place for testing purposes?   Also according to the schematics, the left slingshot is ran through the Q9 transistor on the driver board.  I tested the transistor and it appears to be good, but do you suppose it might not be?