HP Compaq Presario,Presario R4000 Maintenance And Service Manual page 162

Removal and Replacement Procedures
11. Turn the system board upside down with the rear panel
toward you.
12. Insert a flat blade tool into the notch on the RTC battery
socket 1 and remove the RTC battery 2.
✎
The RTC battery is included in the Miscellaneous Plastics Kit,
spare part number 383670-001.
Removing the RTC Battery
Reverse the above procedure to install the RJ-11 modem cable,
RTC battery, and system board.
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