14.Replace the memory module(s) (see Replacing the Memory Module(s)).
15.Replace the optical drive (see Replacing an Optical Drive).
16.Replace the hard drive (see Replacing the Hard Drive).
17.Replace the main battery (see Before Working Inside Your Computer).
NOTICE: Before turning on the computer, replace all screws and ensure that no stray screws remain inside the computer. Failure to do so may result in damage to the computer.
18. Turn the computer over and turn it on.
NOTE: If you use a BIOS update program CD to flash the BIOS, press <F12> before inserting the CD so that you can set up the computer to boot from a CD this one time only. Otherwise, you must enter the system setup program to change the default boot order.
19.Insert the flash BIOS update program CD that accompanied the replacement system board into the optical drive. Follow the instructions that appear on the screen. See Flashing the BIOS for further information.
20.Enter the system setup program to update the BIOS on the new system board with the computer Service Tag.