It could still happen, there are a lot of possibilities. How did the roms come, just by themselves or were they in a daughter card? If they were loose roms they could have needed a different pcb/gal that you don't have and in mame it's going to run like it expects the pcb/gal from Turbo 3.1 if it's loaded over that. A rom could be bad but it's kind of early for bitrot and if they were fried you'd get different crcs every read.