162 Removing and Installing PartsSystem BoardRemoving the System BoardCAUTION: To guard against electrical shock, laceration by moving fan blades, orother unexpected injuries, always unplug your computer from the electrical outletbefore opening the cover.CAUTION: The heat sink assembly, power supply, and other components may bevery hot during normal operation. Be sure that they have had sufficient time to coolbefore you touch them.NOTICE: Before touching anything inside your computer, ground yourself bytouching an unpainted metal surface, such as the metal at the back of thecomputer. While you work, periodically touch an unpainted metal surface todissipate any static electricity that could harm internal components.1 Follow the procedures in "Before You Begin" on page 97.2 Remove the computer cover (see "Removing the Computer Cover" onpage 99).3 Remove any add-in cards on the system board (see "Cards" on page 111).4 Remove the processor and heat sink assembly (see "Processor" onpage 145).5 Remove the memory modules (see "Removing Memory" on page 111) anddocument which memory module is removed from each memory socket sothat the memory modules can be installed in the same location after theboard is replaced.6 Disconnect all cables from the system board. Note the routing of all cablesas you remove them so that you can re-route them correctly after installingthe new system board.7 Remove the eight screws from the system board.8 Lift the system board up and out.