Checking the Backup Battery (2640)
Checking the Backup Battery
- Power-off the computer and unplug the AC Adapter
from the computer.
- Turn the computer upside down
- Remove the DIMM cover and backup battery (see 'Backup Battery'
- Measure the voltage of the backup battery.
NOTE: Be careful not to measure the wrong side
of the backup battery.
| Wire |
Voltage (Vdc) |
| Red |
+2.5 to +3.7 |
| Black |
Ground |
- If the voltage is correct, replace the system board.
- If the voltage is not correct, the backup battery has been
discharged. Replace the backup battery.
- If the backup battery discharges quickly after replacement,
replace the system board.
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