I received a 2nd hand Necromancer XEGS Cart that does not work. It does take over the ram (16K?) above $8000 because basic gets disabled, and it goes straight to self-test. Self test only shows 2 rows of blocks in RAM test, instead of 2.5. My new Sys-Check II shows bad ram above $8000 with the cart inserted. I believe this is only a 16K game with no bank switching, hence no chip in the middle. I re-flowed the solder to pretty much all the touchable points on the pcb, no difference.
I haven't looked to see if that 16K addressable space actually has anything in it yet.. Any other ideas? if the ROM chip is bad, can a 27128 EPROM be dropped in its place?