Recovering unmodified Wii from system settings semi-brick
I am having trouble with my Wii being unable to enter the system settings menu (black screen freeze, even in maintenance mode). I have never modded or softmodded it and it's been quite a while since I last used it. All of the data appears to be present and games seem to play, save, and load just fine. On occasion, the Wii sometimes locks up on the health warning screen (no Press A to continue and machine has to be powered off by holding the power button). I also have to manually power on the system -- the Wiimotes don't seem to do it anymore.
I don't have any idea what version of the system software is on the Wii, but the most recent game I've played is Zelda: Skyward Sword.
The perfectionist in me wants to fix it but the pragmatist says just leave it alone since it still (usually) boots and plays games. ;)
Is there a way to fix this without modding? Every thread I can find assumes the console is already modded or advises the user to mod the system. Or, should I just leave it alone?