Semi or Partial Brick
A partial brick occurs when a user uploads a System Menu update from a region different than his own. Updates designed for other regions will decrease the functionality of the Wii main menu. The game will start up but the Wii system menu will not.
Banner Brick
A banner brick happens when a user installs a channel that contains a banner with an invalid image size. It's the likely cause of the brick if the screen freezes at the "Health and Safety" screen. The message "System Files are Corrupted" may appear.
Full Brick
This term describes the complete malfunction of the Wii system menu. At start-up, the user will only see an Opera error message instead of the Wii's typical warning screen. A full brick could also leave the screen black even though the Wii is turned on.
Low Level Brick
A low level brick is a type of malfunction to the booting, or start-up process. If the process is corrupted, the user will only see a black screen similar to the symptoms experienced with a full brick.
Error 003 Brick
An error 003 brick occurs when system menu of version 4.2 or higher is installed onto a Korean Wii console without the proper Korean region code. The error message "Error 003" will show on start up. The main menu of the Wii console will not be operable but the game should start.
Prevention
Only install updates to your Wii's firmware that match your region. Play in your region as well and avoid deleting critical system files. Don't uninstall unofficial channels or system file modifications.