Dell OptiPlex 755 User Manual page 54

3. Unpack the new processor, being careful not to touch the underside of the processor.
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. If the release lever on the socket is not fully extended, move it to that position.
5. Orient the front and rear alignment-notches on the processor with the front and rear alignment- notches on the socket.
6. Align the pin-1 corners of the processor and socket.
1 processor cover 6
2 tab 7
3 processor 8
4 processor socket 9
5 center cover latch
NOTICE: To avoid damage, ensure that the processor aligns properly with the socket, and do not use excessive force when you install the processor.
7. Set the processor lightly in the socket and ensure that the processor is positioned correctly.
8. When the processor is fully seated in the socket, close the processor cover.
Ensure that the tab on the processor cover is positioned underneath the center cover latch on the socket.
9. Pivot the socket release lever back toward the socket, and snap it into place to secure the processor.
10. 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.
11. Apply the new thermal grease to the top of the processor.
12. 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 tighten the two captive screws.
NOTICE: Ensure that the heat sink assembly is correctly seated and secure.
release lever
front alignment-notch
socket and processor pin-1 indicator
rear alignment-notch