CHAPTER 5: Upgrading Your Computer58Replacing the power supplyTo replace the power supply:1 Follow the instructions in “Preventing static electricitydischarge” on page 44.2 Remove the two side panels by following the instructionsin “Removing the left side panel” on page 45 and“Removing the right side panel” on page 46. Make surethat you unplug the computer’s external power cable.3 Disconnect the power supply cables from allcomponents (such as hard drives, optical and diskettedrives, and the system board), noting their locations andorientation. (You will reconnect the cables after youinstall the new power supply.)4 Remove the four Phillips screws that secure the powersupply to the case.ToolsYou need a Phillips screwdriver to replace the power supply.WarningTo avoid exposure to dangerous electrical voltages and moving parts, turnoff your computer, then unplug the power cord and modem cable before openingthe case.Phillips screwsPhillips screws