I installed nvram on 7 pins today (totan, mm, ijpa, hurricane, cc, ww, and DM). All went well with the exception of DM.
When I put the MPU back in a stupidly connected the ribbon cable from Aux PCB Assembly to J201 and the ribbon from the dmd board to the aux PCB connector on the MPU.
When I fired the game up, behavior was obviously weird. I turned the pin off and checked my ribbon cables to double check/reseat my ribbon cables still not realizing that the aux/dmd ribbons were swapped. Turned the pin back on and there was no activity at all.
Corrected the that mistake but now no joy.
MPU top and bottom leds are solid and middle led is now blinking every second or so.
Now I don't know if I made a mistake with the NVRAM install or damaged a board with the ribbon swap. Swapped NVRAM chip with a known good chip as well.
I clipped the old ram at the chip and removed the pins one at a time, desoldering with my hakko. There are no solder bridges and the pads were nice and clean on both sides before installing the nvram.
W3/R93 are correct.
Currently going through all of our pins for battery elimination (30 or so to go).