My thoughts are if you replaced your batteries with the power off you lost your settings (why its booting into audit mode) and the game is no longer set to Free Play. Though i’m not sure if i’m understanding what you mean by adding a credit. Via coin switches or just hitting start button? The start button won’t add a credit, it starts a game if you have credits. Unless it is set to Free Play then you don’t need any credits.

But the first issue you mention sounds like a possible switch matrix issue. At least the way I interpreted it. Lock a ball, then game registers outhole switch. You can use switch edge test to see what the mpu is registering when you trigger that lock switch. If you see more than just the ball lock switch displayed, that is a problem. This is a quick, non-evasive test so if its not that you havent lost anything... lol

Now if you do see multiple switches recognized we can go down that path to resolve it.

The way the ball will sometimes sit in the outhole without it ending/advancing to next ball makes me think the whole switch problem may be the outhole switch. Sounds like it may be gapped improperly, or maybe the wiring lugs are mashed together or the tensioner leaf is making contact with the other side of the switch etc...

Centaur has 5 balls to keep track of though, so it's possible maybe one of the other ball trough switches is out of adjustment or something like that too. Switch test is your friend here, as completist suggested. See if it recognizes the ball in the outhole, and that it notices when you remove the ball as well. Also, be sure all drop targets are up and all balls are removed from game before beginning switch test. The display should read "0" if no switches are closed.

Sorry i mixed your game up with another one i was helping with.

It sounds like the game is detecting the eject hole switches and ball trough switches in switch test. I guess you may have to try to catch the game while it's acting up, then put it into switch test and see if there are any active switches it's not detecting.

I think macro specialties caries those

I'd suggest either replacing the battery holder with a remote battery pack or you can replace the RAM chip with an NVRAM and get rid of the batteries entirely.

If using a remote battery pack (pic below), you can solder the wires from the pack right to the board (and possibly extend the wires from the board and run them all the way to the front of the cab for easy access to the battery pack thru the coin door)...Pinwiki should have instructions.

Any electronics store should have them for purchase, as well as pinball parts places like Marco Specialities, The Pinball Resource, Pinball Life, etc.

NVRAM would require replacing the RAM chip, which may be difficult if it isn't socketed. Not sure if you are good with board work though, may not be a problem for you.

Either way, no batteries should be the reason why it keeps booting into bookkeeping mode.
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