How to Replace Fujitsu Lifebook N Series CMOS Batteries

The CMOS on your Fujitsu LifeBook N-series notebook is a small, battery-powered chip built into the computer's motherboard. It stores basic information that your computer needs to operate. Most importantly, it stores your LifeBook's time and date settings. But like any battery-operated device, your CMOS will stop working once the battery dies. Then, every time you restart your LifeBook laptop, the time and date settings will reset to the factory default. The bad news is that you must completely dismantle your laptop to access the battery.

Turn off your Fujitsu LifeBook laptop using the operating system. Disconnect the AC power adaptor from the laptop. Close the display panel and place the laptop face down on a secure, flat surface. Rotate the computer so the front opening edge is facing toward you. Remove the battery pack from its compartment along the top edge of the laptop's bottom casing.

Press on the release button securing the CD/DVD drive to the lower left corner of the laptop. Pull the drive out of its compartment and set it aside.

Remove the single Phillips-head screw securing the large hard drive compartment to the right side of the laptop's bottom casing. Remove the cover from the laptop. Gently lift the hard drive out of its compartment, then disconnect the large ribbon cable from the back of the hard drive. Remove the hard drive from the laptop. Disconnect the ribbon cable from its motherboard connector inside the empty hard drive compartment.

Locate the wireless card inside the hard drive compartment. Use a pair of tweezers to disconnect the two antenna cables from the card. Release the locking tabs securing the wireless card in place. Lift the card out of the laptop and set it aside. Remove all Phillips-head screws from the bottom casing.

Place the laptop face up and open the LCD panel. Use a flathead screwdriver to pry the keyboard strip from the laptop. The keyboard strip is the thin plastic strip situated above the top row of keyboard keys. Grasp the bottom edge of the keyboard and place it face down on the laptop's surface. Disconnect the keyboard's ribbon cable from the motherboard. Remove the keyboard from the laptop.

Locate the memory module exposed by the keyboard. Spread the retaining clips on each side of the module. Tilt it upward and then remove the module from its memory slot. Store the module in a static-free plastic bag.

Remove the remaining Phillips-head screws securing the metal motherboard cover to the laptop's base. Disconnect the touchpad cable extending from the motherboard cover to its connector on the motherboard. Remove the cover from the laptop completely.

Locate the yellow CMOS battery in the upper right corner of the motherboard. Disconnect the battery cable from the motherboard and then lift the battery out of its compartment. Throw the old battery away.

Reverse this procedure to install the new battery and reassemble your laptop.


Use an anti-static wrist strap or some grounding device to prevent electrical damage to your LifeBook's motherboard and sensitive components.

Things You'll Need

  • Phillips-head screwdriver
  • Tweezers
  • Flathead screwdriver
  • Anti-static wrist strap
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About the Author

Ezekiel James began as a music writer in 2003. Since then, James has served as a writer for several music, technology and design publications. His work has been published on eHow, and in print for the "The Potrero View" and "Punk Planet." James is currently pursuing a Bachelor of Arts degree in journalism from Portland State University.