Dell Inspiron 16 Plus 7640 Owner's Manual page 49

Figure 24. Installing the processor fan
Steps
1. Place the processor fan on the palm-rest and keyboard assembly.
2. Align the screw holes of the processor fan with the screw holes on the palm-rest and keyboard assembly.
3. Replace the two screws (M2x5) that secure the processor fan to the palm-rest and keyboard assembly.
4. Connect the processor fan cable to its connector (FAN1) on the system board.
Next steps
1. Install the base cover.
2. Follow the procedure in After working inside your computer.
Removing and installing Customer Replaceable Units (CRUs) 49