If even if they are corrupted, just erase and reprogram, the data should be easily available 
@joeks: thanks!
That's what I thought

And, no thanks you're welcome!
@etienne I had a brief look at the board yesterday and didn't see any acid damage at first sight.
The Nintendo filter-board however, has a homemade burnt trace as you can see on the pic.
I tried both sides (part- and solderside) of the Jamma connector when the normal side wasn't giving a picture

Yeah, real stupid I know.