Dell Inspiron 1428 (Late 2009) - Manual (Page 42)

42 Processor Fan and Heat Sink Assembly
5 Replace the three screws that secure the processor fan to the system board.
6 Connect the processor fan cable to the system board connector.
7 Replace the base cover (see "Replacing the Base Cover" on page 34).
8 Replace the battery (see "Replacing the Battery" on page 14).