If MacCheck detects a logic board failure:
1) Shut down your Macintosh by selecting Shut Down from the Finder's Special
menu.
2) Hold down the Shift key while restarting your Macintosh. This lets the
computer start up without loading any system extensions.
3) Run MacCheck again. If MacCheck still detects a logic board error, contact
the Apple Assistance Center or your Authorized Apple Service Provider.