I’d placed an order for some replacement 4116 DRAM. Apparently these days it’s really hard to source so I took a looksee and found a couple guides that show how to use 4164 (more common) DRAM in the same sockets.
Some 4164 was ordered from Jameco Electronics in California.
This guide, called “4116 to 4164” was the one I used to convert the 4164 to be able to be used in a 4116 socket. The 4116 has one less address line so the RAS/CAS allows for 4x the amount of memory in the 4164- we just don’t use one address line (tie it high) and connect up only the ground and +5V, compared to the +12, +5 and -5 supplies the 4116 needs.
Fit them in place:
Powered up and BEEEEEEEEEEEEEEEEE, same result.
Continuation of troubleshooting to follow.