Hey Bruce,

If you have extra 5101 RAM you could try that in the board. It does sounds like it could be bad memory. Unfortunately in order to try a different 5101, you need to remove the existing RAM that's soldered to the MPU & install an IC socket (but you would need to do that for an nvram upgrade anyway).

I should have an Gottlieb Sys1 NVRAM option available again later this year. I actually had a module available last year, for a bit, from Pinsider @cactusjack who had some extra boards made up from when he upgraded some machines. The board was pretty large, so I shrank it down to about the size of the 5101 nvram I sell. I just need to send it off on my next PCB order (which should be happening relatively soon). At this point, I'd expect March/April time-frame I may have some of those for sale again (only in the *NEW* compact design). Just wanted to let you know that was coming..

https://www.pinitech.com/products/gottlieb_sys1_nvram.php (out-of-stock currently, just a link from what was being sold last year)

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http://www.pinitech.com - "Pinball Inspired Technology"
NVRAM, Bally/Stern LED Displays & Mods for pinball machines

If the credits decrease from 68 during playing, then the 5101 CMOS RAM is probably OK, and the problem is the RAM is not getting backup power while game is turned off. If there is still the original Data Sentry nicad on CPU board, remove it NOW to prevent damage. Replace with 1F / 5.5V Goldcap (keeps memory for 2-3 months without AC power) or 3 AA batteries and a series diode to prevent batteries being recharged.

Ah good point I was just assuming the battery voltage was solid or had been checked.

The Data Sentry (brown box looking thing) is the battery.. and if it's still on the board, there's little doubt it's dead and *hopefully* hasn't caused damage to the board. Clay has some info on replacing the Data Sentry battery here -- http://www.pinrepair.com/sys1/#battery