IBM 760C/CD (9546) Clock Radio User Manual


 
Note: Signal lines, not used in these steps, are used
for communication between the system and
the battery.
3. If the voltage is less than +11.0 V dc, the battery pack
has been discharged. Recharge the battery pack.
If the voltage is still less than +11.0 V dc after
recharging, replace the battery.
Note: If the voltage of the battery pack is 0 V, it is
not defective.
4. 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.
If the resistance is not correct, replace the battery
pack.
If the resistance is correct, replace the DC/DC card.
Checking the Car-Battery Adapter
1. Unplug the Car-Battery Adapter cable from the
computer.
2. Plug the Car-Battery Adapter into the cigarette lighter
socket.
Note: If the adapter is already plugged in, reseat it.
3. Measure the output voltage of the Car-Battery
Adapter cable. See the following figure:
2
1
If the voltage is correct, the Car-Battery Adapter
is working correctly. Check that the computer
runs with the AC Adapter. If it runs correctly
with the AC Adapter, check the system board. If
the problem still remains, replace the following
FRUs one at a time.
Terminal Voltage (V dc) / Signal
1 +0 to +13.5
2 Send
3 Thermal
4 Ground ()
5 Select
Pin Voltage (V dc)
1 +19.0 to +21.0
2 Ground
352 IBM Mobile Systems - ThinkPad HMM Volume 3