Kenny, I asked about the playfield unplugged because sometimes when
there's a stuck playfield switch, it will make relays or units
continuously fire. If everything is plugged in -except- the playfield,
and the relays in the head stop firing, it may point you to something
wrong on the playfield.
Re: the score motor stops when you manually pull the reset bar, I had
that recently happen to my 2-player GTB Airport. For me, it ended up
being a reset relay with a poorly gapped switch.
Very generally speaking, during reset a few things have to happen; score
reels reset, ball count goes back to beginning, etc, and one of these
things is not indicating to the machine that it's done - even though it
may be. Things that step down need the score motor to give it pulses
for the stepping; something is indicating that it still needs pulses, so
on it runs.
That's why I mentioned looking at the switches on relays involved in the
start-up sequence.