Lenovo ThinkCentre M70a Hardware Maintenance Manual page 117

Your computer has a special type of memory that maintains the date, time, and settings for built-in features,
such as parallel connector assignments (configurations). A coin-cell battery keeps this information active
when you turn off the computer.
The coin-cell battery normally requires no charging or maintenance throughout its life; however, no coin-cell
battery lasts forever. If the coin-cell battery fails, the date and time information is lost. An error message is
displayed when you turn on the computer.
Replacement procedure
1. Remove the computer stand. See "Computer stand" on page 61.
2. Remove the rear cover. See "Rear cover" on page 65.
3. Remove the optical drive. See "Optical drive" on page 66.
4. Remove the optical drive holder. See "Optical drive holder" on page 69.
5. Remove the system board shield. See "System board shield" on page 71.
6. Remove the VESA mount bracket cover. See "VESA mount bracket cover" on page 74.
7. Remove the VESA mount bracket. See "VESA mount bracket" on page 76.
8. Remove the storage drive. See "Storage drive and storage drive bracket" on page 78.
9. Depending on your computer model, refer to one of the following to replace the coin-cell battery.
• M70a
Figure 111. Removing the coin-cell battery
.
Chapter 6 Hardware removal and installation
111