I am working on a World Cup board set on the bench. I have got everything working except saving settings. I have replaced both male and female connectors for the 40 pin interconnect. Replaced all Scanbe sockets on the MPU and Driver board. Installed NVRAM. Installed MOSFT upgrade on the Driver board for the lamp matrix. No battery corrosion to speak of, fairly clean board. Ran through all Pincoder test ROMs and all okay. Ran through built in diagnostics and all okay. Only problem remaining is saving the settings. On reboot it comes up with 01 04. Turning off and on will get it to boot into attract mode. I can add credits and even play a simulated game. Turning off and back on and I get the 01 04 most of the time, every once in awhile it will come back up into attract mode with credits, etc. saved but mostly it comes back to 01 04.
Not sure what to check on the NVRAM to see what is wrong. Does anyone have experience with this problem?
Thanks for any insight anyone can give.