Dell Precision 490 Desktop User's Guide - Page 137

Back to Contents Page System Board Dell Precision™ Workstation 490 User's Guide Removing the System Board Replacing the System Board 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. 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. Removing the System Board 1. Follow the procedures in Before You Begin. 2. Remove the computer cover (see Removing the Computer Cover). 3. Rotate the hard-drive carrier out of the computer (see Rotating the Hard-Drive Carrier Out of the Computer). 4. Remove the processor access door assembly: a. Remove the green screw that attaches the processor access door assembly to the system board and to the computer chassis. b. Lift to remove the processor access door assembly from the computer. 5. Use a long Phillips screwdriver to loosen the four captive screws on the sides of the heat-sink assembly. CAUTION: The heat-sink assembly may become very hot during normal operation. Ensure that it has had sufficient time to cool before you touch it. 1 heat sink assembly 2 captive screw housing (4) 6. Lift to remove the heat-sink assembly from the computer. 7. Disconnect the optional speaker connector (if installed) from the system board. 8. Disconnect the card fan from the system board connector labeled FAN_CCAG. (See System Board Components.)