Performing these steps incorrectly could damage your system board. For technical service, see "Contacting Dell" in the Owner's Manual. CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide. CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover. CAUTION: The heat-sink assembly can get very hot during normal operation. Be sure that the assembly has had sufficient time to cool before you touch it. NOTICE: Before touching anything inside your computer, ground yourself by touching an unpainted metal surface, such as the metal at the back of the computer. While you work, periodically touch an unpainted metal surface to dissipate any static electricity that could harm internal components. NOTICE: Carefully remove the processor from the socket to avoid permanent damage to the processor. NOTICE: Ground yourself by touching an unpainted metal surface on the back of the computer. NOTICE: You must position the processor correctly in the socket to avoid permanent damage to the processor and the computer when you turn on the computer. 4. Set the processor lightly in the socket and ensure that the processor is level in the socket. When the processor is positioned correctly, press it with minimal pressure to seat it. 5. When the processor is fully seated in the socket, close the processor cover. 6. Pivot the socket release lever back toward the socket and snap it into place to secure the processor. If you installed a processor replacement kit from Dell, return the original heat-sink assembly and processor to Dell in the same package in which your replacement kit was sent. 7. Replace the fan assembly if you removed it. 8. Plug the fan cable into the FAN connector on the system board. 9. Install the heat-sink assembly. 10. Plug the power cable into the 12VPOWER connector on the system board. 11. Replace the computer cover. 12. Connect your computer and devices to electrical outlets, and turn them on. Modem Replacing the Modem 1. Follow the procedures in "Before You Begin." 2. Remove the computer cover. 3. Remove the hard drive. NOTICE: Socket pins are delicate. To avoid damage, ensure that the processor is aligned properly with the socket, and do not use excessive force when you install the process. Be careful not to touch or bend the pins on the system board. NOTICE: When you install the heat-sink assembly, do not touch the thermal interface to prevent damage to the thermal interface material on the interface. NOTICE: If you are not installing a processor upgrade kit from Dell, reuse the original heat-sink assembly when you replace the processor. NOTICE: To connect a network cable, first plug the cable into the network port or device and then plug it into the computer. CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide. NOTICE: Before you remove or install the modem, make sure to disconnect all telephone and network cables from your computer. NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your computer's electronic components. You can do so by touching an unpainted metal surface on the computer chassis. 4. Remove the existing modem: a. Disconnect the modem cable from the modem. b. Use a small Phillips screwdriver to remove the two screws that secure the modem to the system board, and set the screws aside. c. Pull straight up on the attached pull-tab to lift the modem out of its connector on the system board. 5. Install the new modem: a. Align the modem with the screw holes and press the modem into the connector on the system board. b. Connect the modem cable to the modem. c. Use a Phillips screwdriver to replace and tighten the two screws that secure the modem to the system board. 6. Replace the computer cover. Replacing the External Modem Connector 1. Follow the procedures in "Before You Begin." 2. Remove the computer cover. 3. Remove the existing modem. 4. Remove the modem cable from the modem. 5. Remove the external modem connector: a. Remove the screw that secures the external modem connector. b. Slide the external modem connector away from the slot that holds the modem connector in place. c. Lift the modem cable and connector from the computer. NOTE: For easier access to the modem, it may be necessary to remove the power cable from the power connector on the system board. NOTICE: The connectors are keyed to ensure correct insertion. If you feel resistance, check the connectors and realign the card. NOTE: Note the routing of the modem cable as you remove the modem. You must route the cable properly when you replace the modem to prevent the cable from being pinched or crimped. 6. To install a new modem cable and external modem connector: a. Attach the modem cable to the external modem connector. b. Align the exter...