HP COMPAQ 6715S Maintenance And Service Manual page 45

NOTE: These steps also clear CMOS.
Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the
1.
computer on, and then shut it down through the operating system.
Disconnect all external devices connected to the computer.
2.
Disconnect the power from the computer by first unplugging the power cord from the AC outlet and
3.
then unplugging the AC adapter from the computer.
Remove the battery (see
4.
Remove the real-time clock (RTC) battery (see
5.
Wait approximately 5 minutes.
6.
Replace the RTC battery and reassemble the computer.
7.
Connect AC power to the computer. Do not reinsert any batteries at this time.
8.
Turn on the computer.
9.
All passwords and all CMOS settings have been cleared.
Battery on page 41).
RTC battery on page 59).
Preliminary replacement requirements 39