2.Disconnect any telephone or telecommunication lines from the computer.
3.Disconnect your computer and all attached devices from their electrical outlets, and then press the power button to ground the system board.
CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover.
4. Open the computer cover.
NOTICE: Before touching anything inside your computer, ground yourself by touching an unpainted metal surface, such as the metal at the back of the computer. While you work, periodically touch an unpainted metal surface to dissipate any static electricity that could harm internal components.