Checking the Car Battery Adapter (700

only): If the output voltage from the cigarette lighter socket of the car is less than 10.5 V dc, the power-on indicator on the car battery adapter blinks and a noise be heard continuously.

1.Unplug the car battery adapter cable from the connector, if connected.

2.Plug the car battery adapter into the cigarette ligh socket.

Note: If the adapter is already plugged in, be sure unplug the adapter from the cigarette lighter socket, then plug it into the socket again.

3. Measure the output voltage of the car battery adapt cable. See the following figure.

2

1

 

 

 

 

Pin

 

Voltage (V dc)

 

 

 

1

 

+19.0 to+21.0

 

 

 

2

 

Ground

 

 

 

ŸIf the voltage is correct and the power-on

indicator

 

on

the

car

battery adapter is on all th

time, the car battery is working correctly.

Replace

the

voltage

converter. If the problem is

not resolved when the voltage converter is

replaced,

go

to “Checking the Voltage Converter

(700, 700C)”

on

page 77

or

“Checking

the

Voltage

Converter

(720,

720C)” on

page 78.

ŸIf the voltage is outside the normal voltage

range, do one of the following:

–Try the above test procedures using a

different car, if one is available.

–Replace the car battery adapter if the computer works with the AC adapter but

does not work with the car battery adapter.

Note: If

the

output

voltage

from

the cigarette

lighter

socket

of

the

car is

less

than 10.5 V dc, the

power-on indicator on the

car

battery adapter blinks

and

a

continuous

noise

can

 

be

heard. Have

the

car

battery serviced.

 

 

 

 

 

ThinkPad 700, 700C, 720, 720C (9552)73