809-4 is part of the model number. There should be more letters on the serial number plate below the handle. Top number is the model, bottom is the serial number.
all the 809-4x machines I have info on are made for specific casinos - and none are MGM - so finding an exact schematic is unlikely. However, the schematic for the 809-B is probably very close. Typical differences would be things like jackpot bell, tower lights, electric door locks, etc. that aren't relevant for basic game operation.
you can find the paperwork on
http://bingo.cdyn.com/slots/the hidden reels in the top compartment are the X2-X5 units. They are basically pinball machine score reels and they are in the payout multiplier circuit on games with electrically stepped payout counters:
- if you play one coin, the odds unit ties the payout counter directly to the coin out switch on the hopper. Every coin ejected = one step of the payout counter.
- if you play 2 coins, the odds unit connects the X2 unit to the hopper switch. The X2 unit steps for every coin ejected, and connects the payout counter step-up coin every 2 steps. So 2 coins out = 1 payout counter step.
- the X3-X5 units are similar, changing the coin/payout counter stepping ratio appropriately.
the coin lockout coil is the thing behind the coin mech causing the coins to reject. Take a look at the schem to see the switches involved in getting it to power (game ready to accept coins). Also note part of the circuit is feeding the handle release, so with that not working it's pretty safe to assume your issue is above wire 25-1 (schem K10) ... which still leaves a lot of switches and plug connections. A jumper wire or voltmeter can be used to find the issue if a quick visual inspection and what david already mentioned doesn't turn up anything obvious.
the lights are on the schem around H16. Coin accepted light comes on when the payout relay is unpowered (game not paying) and the coin relay is tripped (first coin accepted).
yell if more specific info needed