I recently picked up this machine along with a Monroe in the same style frame as part of a package deal, this one however has some odd problems that aren’t reproducible all the time:

1. Getting a scoring ball in the 1 or 2 pockets sometimes IMMEDIATLY triggers a fever round; a V is shown on the led display; the flippers/arms open once then it goes into alarm/error mode and then requires a reboot as it sounds like an ambulance. (This shouldn’t happen).

However most of the time they function normally and just open the flippers like they are supposed to giving the opportunity to get a fever via the V hole in the center feature like every other hanemono of this vintage.

2. Sometime during a fever it will suddenly go into error mode for no reason; balls are being fired and making it into the center feature past the arms/flippers (I’m not a hanemono newb ) and the machine is full of balls; no overflow happening, etc.

All payouts and everything else work just fine; this machine has vintage payout mechanics so it pays out just fine even without electricity. Any ideas? I’m thinking must be something in the mystery metal box of obsolete electronic components that might be going out.