When working on the inside of an EM, with the playfield raised,
always ALWAYS put a towel or something like it on the mechanics in
the lower part of the machine. This has 2 advantages: first when something
drops from underneath the playfield (i.e. screws) it's easy to find them
again and second: because you can found these parts there is no danger of
damaging relays etc. because there's a screw sitting between the relays,
stepping units, motor and so on.