> I've never heard of a problem like this. Can you hold down the "R" key on controller 1 and get to the menu to run diags? It is an SRAM not a BRAM error? It's possible your SRAM went bad. If that's all that went bad you can replace it although it's a pain because the chips are hard to find and it's probably a surface mount IC.
> Here is Dumper hardware wisdom #1: Check the power supply first!
It happen all time for me, I just take out the ram (inside the machine ) and replace it back. then it work fine agian.