CHECKOUT GUIDE
Note
In this case, the battery pack is over-discharged.
It takes at least 3 hours to recharge the battery
pack even if the indicator does not turn on.
4. If the voltage is still less than
+
11.0 V dc after
recharging, replace the battery.
5. If the voltage is more than
+
11.0 V dc, measure the
resistance between battery terminals 3 and 4. The
resistance must be 4 to 30 K ohm.
6. If the resistance is not correct, replace the battery
pack. If the resistance is correct, replace the system
board.
Checking the Backup Battery:
Do the following:
1. Power off the computer and unplug the AC Adapter
from the computer.
2. Turn the computer upside down.
3. Remove the backup battery (see “Removal and
Replacement” section of each model).
4. Measure the voltage of the backup battery. See the
following figure.
Note
Be careful not to measure the wrong side of the
backup battery.
If the voltage is correct, replace the system board.
If the voltage is not correct, replace the backup
battery.
If the backup battery discharges quickly after
replacement, replace the system board.
Wire
Voltage (V dc)
Red
+
2.5 to
+
3.2
Black
Ground
38
Summary of Contents for ThinkPad 770E
Page 80: ...FRU REMOVALS AND REPLACEMENTS 74...
Page 102: ...FRU REMOVALS AND REPLACEMENTS Locate the microphone spacer and cable 96...
Page 111: ...FRU REMOVALS AND REPLACEMENTS ThinkPad 770 770E 770X and 770Z 105...
Page 123: ...PARTS LIST Parts List ThinkPad 770 770E 770X and 770Z 117...
Page 136: ...IBM Part Number 37L5152 Printed in U S A S1 L 9621 2...
