System Files Are Corrupt

I've gotten into fixing consoles and recently came across two wii's that were broken. One of them I was able to get up and running pretty fast, the other one however is uh, questionable. It's got the dreaded "System Files Are Corrupted" screen, and normally I would be able to access different settings to attempt to fix it. But the previous owner has seemed to try to fix it with a factory reset, sending the wii back to its factory default, and as soon as I try to set it up the screen flashes a little, and then just prompts me with the Corrupted file screen. Even when trying to boot to matienence I get the same issue. So I'm wondering if somewhere out in the wii nerd/homebrewing world if there is a piece of 3rd party software or a random button assignment that would give me some kind of access to any type of settings to try to fix it.