problem with the RAM/ROM "test" is that it simply checks to see if the data lines are responding, not if the data is good.
you'd have to download the appropriate version dataset for what you have and do a ROM by ROM compare.
...and, unless you have kept a particular old version (for a glitch or something) or have a weird china clone of some kind, you likely might only be able to download the last version and just burn a "new" set of chips.
eliminate that completely as a source of the error.