Dell Inspiron 15R (N5110, Early 2011) - Manual (Page 80)

80 Processor Module
Replacing the Processor Module
1 Follow the instructions in "Before You Begin" on page 9.
NOTE: If a new processor is installed, you will receive a new thermal-cooling
assembly, which will include an affixed thermal pad, or you will receive a new
thermal pad along with documentation to illustrate proper installation.
2 Align the pin-1 corner of the processor module with the pin-1 corner of the
ZIF socket, then insert the processor module.
NOTE: The pin-1 corner of the processor module has a triangle that aligns with the
triangle on the pin-1 corner of the ZIF socket.
1 ZIF socket 2 processor module
3 pin-1 corner 4 ZIF-socket cam screw
1
2
4
3