I have a Silverball Mania (1979 Bally) and it has an AnyPin NVRAM chip in it. It has a problem holding the game adjustment settings though. It'll be fine for a bit, then things will become scrambled, like the high score, credits, book keeping, will just change at random.
I checked the socket that was soldered in for the AnyPin, and touched up the solder to make sure it was connecting on both sides of the board. The board has had some minor battery damage near the edge (I think) because the outside ground strip has solder along the edge, but it looks like it was done by someone that knew a thing or two about it. Nothing else shows any sign of damage, the chips/sockets and components are clean and healthy looking. I've removed and reseated all the socketed chips, and reflowed all the solder on the connector pins.
Could the AnyPin nvram be faulty? Doesn't seem that likely that it would be, but any input is greatly appreciated, thanks.