Checking

the

AC

Adapter:

If the Power-On

 

 

 

indicator

does not turn-on, check

the

power

cord of

the

AC

adapter

for

correct

continuity

and

installation.

 

 

1. If

any

noise can be heard from the

AC adapter when

it is plugged into the ac power outlet, replace the AC

adapter.

 

 

 

 

 

 

 

If

no noise can

be heard

from

the AC

adapter,

go

to

step

3.

 

 

 

 

 

 

 

2.If a noise is still heard from the new AC adapter, suspect the computer. Replace the AC adapter with

the original

one, then go

to the next step. If no nois

is heard from the new AC

adapter, the original AC

adapter is

defective.

 

3.Unplug the AC adapter cable from the computer and measure the output voltage at the plug of the AC

adapter cable. See the following figure.

 

 

2

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pin

 

 

 

 

 

 

Voltage

(V

dc)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

+19.0 to+21.0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ÿ

If

the

voltage

is

not

correct,

go

to

the

next ste

4.

Unplug

the

AC

adapter

cable

from

the

ac

power outlet

 

and

wait for

a few minutes.

 

 

 

 

 

 

5.

Plug

the

AC

adapter

cable

into

the

ac

power

outlet.

6.

Measure

the

output

voltage

of

the

AC adapter.

 

ŸIf the voltage is still not correct, replace the AC adapter.

ŸIf the voltage is correct, plug the AC adapter cable into the computer and try the failing operation again.

Ÿ If

the problem

goes

away, suspect the continuity

or

installation of

the

AC adapter cable.

ŸIf the problem is not corrected, replace the voltage converter.

72 IBM Mobile Systems HMM