Dell Dimension E521 - Manual (Page 40)

13. Secure the hard drive cable, CD/DVD drive data cable, and the front panel ribbon cable to the securing clip on the side of the power supply.
14. Replace the computer cover (see Installing the Computer Cover ).
15. Connect your computer and devices to an electrical outlet, and turn them on.
16. Verify that the computer works correctly by running the Dell Diagnostics (see Dell Diagnostics ).
Processor
Removing the Processor
1. Follow the procedures in Before You Begin .
2. Remove the computer cover (see Removing the Computer Cover ).
3. Carefully disconnect and move any cables that are routed over the heat sink assembly.
4. If your computer includes a card retention mechanism to secure the x16 card in place from the top:
a. Pivot the mechanism upward and gently squeeze in on the sides to release the mechanism from the two tab slots holding it in place.
b. Set the retention mechanism aside.
5. Loosen the captive screw on each side of the heat sink assembly.
6. Rotate the heat sink assembly upward, and remove it from the computer.
Lay the heat sink assembly down on its top, with the thermal grease facing upward.
NOTE: Double-check all cable connections to make sure they are secure.
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions located in the Product Information Guide.
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.
CAUTION: Despite having a plastic shield, the heat sink assembly may be very hot during normal operation. Be sure that it has had sufficient time
to cool before you touch it.
NOTICE: To prevent damage to the processor, press on the heat sink assembly toward the front of the computer to help break the thermal grease
bond between the heat sink and the processor.
1 heat sink assembly 2 captive screws (2)
NOTICE: Unless a new heat sink is required for the new processor, reuse the original heat sink assembly when you replace the processor.