Checking  the  ac  adapter 
You  are  here  because  the  computer  fails  only  when  the  ac 
adapter  is  used. 
v  If  the  power  problem  occurs  only  when  the  port 
replicator  is  used,  replace  the  port  replicator. 
v  If  the  power-on  indicator  does  not  turn  on,  check  the 
power  cord  of  the  ac  adapter  for  correct  continuity  and 
installation. 
v  If  the  computer  does  not  charge  during  operation,  go  to 
″Checking  operational  charging.″ 
To  check  the  ac  adapter,  do  the  following: 
1.  Unplug  the  ac  adapter  cable  from  the  computer. 
2.  Measure  the  output  voltage  at  the  plug  of  the  ac 
adapter  cable.  See  the  following  figure: 
 
2
1
(16-10V)
 
 
Pin  Voltage  (V  dc) 
1  +15.5  to  +17.0 
2  Ground 
 
3.  If  the  voltage  is  not  correct,  replace  the  ac  adapter. 
4.  If  the  voltage  is  acceptable,  do  the  following: 
v  Replace  the  system  board. 
v  If  the  problem  persists,  go  to  “Product  overview”  on 
page  43.
Note:
  Noise  from  the  ac  adapter  does  not  always  indicate 
a  defect. 
Checking  operational  charging 
To  check  whether  the  battery  charges  properly  during 
operation,  use  a  discharged  battery  pack  or  a  battery  pack 
that  has  less  than  50%  of  the  total  power  remaining  when 
installed  in  the  computer. 
Perform  operational  charging.  If  the  battery  status  indicator 
or  icon  does  not  turn  on,  remove  the  battery  pack  and  let  it 
return  to  room  temperature.  Reinstall  the  battery  pack.  If 
the  charge  indicator  or  icon  still  does  not  turn  on,  replace 
the  battery  pack. 
If  the  charge  indicator  still  does  not  turn  on,  replace  the 
system  board.  Then  reinstall  the  battery  pack.  If  it  is  still 
not  charged,  go  to  the  next  section. 
Checking  the  battery  pack 
Battery  charging  does  not  start  until  the  Power  Meter 
shows  that  less  than  95%  of  the  total  power  remains; 
Checkout  guide  
38  R50/R50p,  R51  Series