System information

RTC battery
Description Spare part number
RTC battery 621565-001
Before removing the RTC battery, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn
the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet
and then unplugging the AC adapter from the computer.
4. Remove the battery (see
Battery on page 50).
5. Remove the service cover (see
WLAN module on page 52).
Remove the RTC battery:
1. Insert a non-conductive, flat-tip, tool (1) into the notch (2) on the side of the RTC battery socket.
2. Remove the RTC battery (3) from the socket on the system board.
Reverse this procedure to install the RTC battery. When installing the RTC battery, be sure the “+” sign
faces up.
58 Chapter 4 Removal and replacement procedures