Wii froze while updating
If the Wii NAND filesystem is corrupt, the System Menu's IOS is missing or invalid, or the System Menu executable is missing or invalid, then the system will refuse to boot and nothing will be displayed on the screen.Depending on the exact cause of failure, Preloader or Boot Mii/boot2 can fix (and are required to fix) this sort of brick, assuming they are installed and the system boots far enough to run them.
Because of this it's impossible to fix using software unless you have Boot Mii installed (as boot2), or you use a Savemii Dongle with an autoboot disc. The Wii displays nothing and you are presented with a black screen.That menu can be triggered by holding down all D-Pad buttons on the GC controller plugged into slot 4, a tab inside the controller needs removed in official GC controllers.Every time the file at the boot mail entry URL installed by wc24app is updated, every Wii that already downloaded the boot mail would download again and wakeup for title booting again.The term is often used in situations where modifying a system's firmware (without necessarily making any alterations to the machine's hardware) has caused it to become inoperable.
A Semi/Partial Brick occurs when a System Menu update from the wrong region is installed on a Wii or some resources have been otherwise damaged, breaking some (but not all) of the functionality of the System Menu.
Since boot2 is required to be working and able load an IOS before the system can run, any errors in this process will render the system inoperable.