IBM THINKPAD 760C/CD (9546) - Manual (Page 365)

a. DC/DC card
b. System board
If the problem is not resolved when the system
board is replaced, go to “Undetermined
Problems” on page 371.
If the voltage is outside the normal voltage
range, do one of the following:
– Try these test procedures in a different car,
if one is available.
– Replace the Car-Battery Adapter if the
computer works correctly with the AC
Adapter.
Note: If the output voltage from the cigarette lighter
socket of the car is less than 10.5 V dc, a
continuous noise may be heard. The condition of
the car battery should be checked by appropriate
service personal.
Checking the Backup Battery
1. Power-off the computer and unplug the AC Adapter
from the computer.
2. Open the keyboard, and remove the diskette
drive/CD-ROM drive, the battery pack, and the hard
disk drive.
3. Remove the top cover and keyboard unit.
4. Open the keyboard unit; then remove the keyboard
card.
5. Remove the backup battery from the keyboard card.
(Refer to “1200 Backup Battery, Speaker, Standby
Battery” on page 425 to remove the battery.)
6. Measure the voltage of the backup battery. See the
following figure:
ThinkPad 760 (9546, 9547) 353