Reseting power manager didn't do anything. The link to the manual on gamba is broken, but I found one elsewhere.

To quote the manual

RAM failure occurs

(eight-tone error

chord sequence

sounds after startup

chord)

I'm guessing the on-board RAM has died. The expansion card went last week and the on-board this week... something might be off with the memory controller. Assuming it is the on-board RAM, I'm really not sure what to do except for a 130$ logic board replacement.