I had a recent service call for a Stern Big Buck Hunter Pro, the issue was the buck wouldn’t return to the right, home, position. I’m not very familiar with this mechanism and controls so I had some figuring out to do.
A previous tech had already replaced the motor, there was also another new motor in the bottom of the cabinet. The customer explained that when he bought the replacement motor it was advised to get another one as a spare, good advice.
I plugged in the new one just to verify the motor wasn’t bad. It didn’t do anything so I didn’t the motor was the issue. I found that when the screw was turned a few times to move the buck back to the right an inch or so, it moved all the way back to the left again, but still not to the right.
There are 2 big relays under the playfield that control the left and right movement. I cleaned the terminals and it worked correctly about 3 times then was stuck in the left position again. Thinking maybe one was bad, I swapped them. Still no change. Since it did work both ways a few times, that eliminates things like fuses or the boards.
The only thing left to check now is the left and right limit switches. Not only do they tell the game that the buck is at its full left or right limit, they also cut out the relay so it can’t be moved past it’s limit point.
Cleaning the switch terminals with a fiberglass eraser and spraying the switch with contact cleaner got the buck working again.
Interestingly the left and right relays and the switch’s, both with wiring pigtails, are still available from Marco Specialties. I’m sure these are factory leftovers so if you have a Big Buck Hunter Pro I’d suggest you grab some spares before they’re gone. Links are below…..
FYI: The relays with the pigtails are cheaper from Marco than just the relays from Digikey.
Links for parts:
https://www.marcospecialties.com/pinball-parts/511-5220-00
https://www.marcospecialties.com/pinball-parts/511-5220-01
Here’s the link for the relays from Digikey if Marco runs out. The part number is right from the Stern manual.
This is for the switches, even though there’s different listings for left and right, they are interchangeable. I know because I swapped them during testing so get 2.
But just to be sure double check the switches on your game match the switches in the pictures.
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