Dell Dimension C521 Service Manual page 26

2. Unpack the new processor, being careful not to bend any of the processor pins.
NOTE: 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.
3. If the release lever on the socket is not fully extended, move it to that position.
4. Align the pin-1 corners of the processor and socket.
1 pin-1 corner 2
4 socket
NOTICE: To avoid damage, ensure that the processor aligns properly with the socket, and do not use excessive force when you install the processor.
5. Set the processor lightly in the socket and ensure that the processor is positioned correctly.
6. While lightly pressing down on the processor, rotate the release lever back toward the system board until it snaps into place, securing the processor.
7. Clean the thermal grease from the bottom of the heat sink.
NOTICE: Ensure that you apply new thermal grease. New thermal grease is critical for ensuring adequate thermal bonding, which is a requirement for
optimal processor operation.
8. Apply the new thermal grease to the top of the processor.
9. Install the heat sink assembly:
a. Place the heat sink assembly back onto the heat-sink assembly bracket.
b. Rotate the heat sink assembly down towards the computer base and ensure that the two captive screws are properly aligned with the holes in
the system board.
c. Tighten the two captive screws.
NOTICE: Ensure that the heat sink assembly is correctly seated and secure.
processor 3 release lever