The slam switch under the playfield is supposed to be open with a large gap. There is another one in the backbox, (I think that one is supposed to be closed) and on the coin door. Also check that the tilt mech by the left flipper button in the cabinet is not closed.

It sounds like you disturbed something while "shopping" it. It is easy to knock a relay out of alignment. I would visually inspect every relay in the cabinet and backbox for proper position and travel. Also check the wires where they attach at the relays. They can short very easily. I have run across bent tabs, solder blobs, worn through insulation, etc.

If it worked before, then do not take apart the stepper unit. Do not attempt to disassemble the score motor!

Glad you seemed to have solved your first problem. Go through Clay's guide and clean/adjust/tighten the relays. Rebuild the flippers and get new eos switches for them. Once you do this, your game will be trouble-free for a long time.