Your computer has a special type of memory that maintains the date, time, and settings for built-in features,such as parallel-port assignments (configuration). A battery keeps this information active when you turnoff the computer.The battery normally requires no charging or maintenance throughout its life; however, no battery lastsforever. If the battery fails, the date, time, and configuration information (including passwords) are lost. Anerror message is displayed when you turn on the computer.Refer to the “Lithium coin cell battery notice” in the Safety, Warranty, and Setup Guide that came with yourcomputer for information about replacing and disposing of the battery.To replace the battery, do the following:1. Remove all media from the drives and turn off all attached devices and the computer. Then, disconnectall power cords from electrical outlets and disconnect all cables that are connected to the computer.2. Remove the computer cover. See “Removing the computer cover” on page 136.3. Remove the heat sink fan duct. See “Replacing the heat sink and fan assembly” on page 158.4. Depending on your computer model, you might need to remove the PCI Express x16 graphics card foreasier access to the battery. See “Installing or replacing a PCI Express card” on page 139.5. Remove the old battery.Figure79. Removing the battery6. Install a new battery.Figure80. Installing the battery7. Reinstall the PCI Express x16 graphics card if you had removed it. See “Installing or replacing a PCIExpress card” on page 139.8. Reinstall the heat sink fan duct. See “Replacing the heat sink and fan assembly” on page 158.9. Reinstall the computer cover and reconnect the cables. See “Completing the parts replacement” onpage 186.Note: When the computer is turned on for the first time after replacing the battery, an error messagemight be displayed. This is normal after replacing the battery.10. Turn on the computer and all attached devices.144 ThinkCentre M73 Hardware Maintenance Manual
