Toshiba U400 user manual Real Time Clock battery, If the following message is displayed on the LCD

Power and Power-Up Modes

Battery pack

To ensure that the battery pack maintains its maximum capacity, operate the computer on battery power at least once a month until the battery pack is fully discharged. Refer to Extending battery life in this chapter for procedures. If the computer is continuously operated on AC power through an AC adaptor for an extended period, more than a month, the battery may fail to retain a charge. It may not function efficiently over the expected life of the battery and the Battery indicator may not indicate a low-battery condition.

Real Time Clock battery

The Real Time Clock (RTC) battery provides power for the internal real time clock and calendar. It also maintains the system configuration.

If the RTC battery becomes completely discharged, the system loses this data and the real time clock and calendar stop working.

The computer's RTC battery is a lithium ion battery and should be replaced only by your dealer or by a TOSHIBA service representative. The battery can explode if not properly replaced, used, handled or disposed of. Dispose of the battery as required by local ordinances or regulations.

■You can change the settings of the Real Time Clock by pressing F2 in POST.

■After configuring the time and date for the Real Time Clock battery, we recommend that you turn the power status of your computer to "ON" so that the Real Time Clock battery is charged. Refer to Chapter 9 Troubleshooting, for details.

If the following message is displayed on the LCD:

ERROR 0271: Check date and time settings.

WARNING 0251: System CMOS checksum bad-Default configuration used.

Press [F1] to resume, [F2] to setup.

6-4 User’s Manual