3-30 Disassembly and Reassembly
CMOS Battery
The system board uses a CMOS battery to maintain system configuration information. The
battery is a coin-cell battery mounted on the system board (see the following figure). If it fails to
maintain system configuration information, replace it with an identically rated battery from the
same manufacturer.
The battery can explode if it is incorrectly replaced or improperly
discarded. Use only the same type battery or an equivalent type recommended by the
manufacturer when replacing the battery.
Lithium acts as a catalyst when exposed to water and causes spontaneous combustion on
contact. Discard used batteries according to the manufacturer’s instructions.
Removing the battery from the system board causes the system to lose
system configuration information. Prior to removing the battery, run the BIOS Setup Utility (see
Section 2) and print out or write down your system configuration settings. Then you can restore
the system to its previous settings.
If you need to replace the battery, follow these steps.
1. Turn off and unplug the system and any external components connected to it.
2. Remove the system cover (see “Removing the Cover” in Section 3). Observe all safety
precautions when removing the cover.
3. Locate the battery on the system board (see the following figure).

Locating the Battery on the System Board

A – Battery
4. Press down on the battery clip to release the battery from its socket on the system board.
5. Remove the battery and discard in accordance with the manufacturer’s instructions.