if it's really an 809-ZZB, the schematic and other paperwork is on
https://bingo.cdyn.com/slots/if the hopper is running when there's no winning combination on the reels, that'd be a more interesting problem than there is a winner on the reels and the payout counter is not stepping up.
the 809-ZZB is an electrically stepped payout counter. As coin eject, a roller arm closes some switches and a couple of them redundantly step up the payout counter. if there's a problem in the circuit or the payout counter step-up coil is bad, then you get the runaway payout ... but a safety circuit should shut the machine down within a few coins.
if your machine is dumping the hopper, either the safety circuit is disabled or it's not really an 809-ZZB.
if ya can't post pics here due to size and ya don't want to mess with resizing, email highest possible resolution pictures to slotpics@cdyn.com and I'll put them on the above site for people to look at.