Removing  and  replacing  a  FRU 
This  section  presents  directions  and  drawings  for  use  in 
removing  and  replacing  a  FRU.  Be  sure  to  observe  the 
following  general  rules: 
1.  Do  not  try  to  service  any  computer  unless  you  have 
been  trained  and  certified.  An  untrained  person  runs 
the  risk  of  damaging  parts. 
2.  Before  replacing  any  FRU,  review  “FRU  replacement 
notices”  on  page  71. 
3.  Begin  by  removing  any  FRUs  that  have  to  be  removed 
before  the  failing  FRU.  Any  such  FRUs  are  listed  at  the 
top  of  the  page.  Remove  them  in  the  order  in  which 
they  are  listed. 
4.  Follow  the  correct  sequence  in  the  steps  for  removing 
the  FRU,  as  given  in  the  drawings  by  the  numbers  in 
square  callouts. 
5.  When  turning  a  screw  to  replace  a  FRU,  turn  it  in  the 
direction  as  given  by  the  arrow  in  the  drawing. 
6.  When  removing  the  FRU,  move  it  in  the  direction  as 
given  by  the  arrow  in  the  drawing. 
7.  To  put  the  new  FRU  in  place,  reverse  the  removal 
procedure  and  follow  any  notes  that  pertain  to 
replacement.  For  information  about  connecting  and 
arranging  internal  cables,  see  “Locations”  on  page  112. 
8.  When  replacing  a  FRU,  use  the  correct  screw  as 
shown  in  the  procedures.
DANGER
 
 
 
 
Attention:  After  replacing  a  FRU,  do  not  turn  on  the 
computer  until  you  have  made  sure  that  all  screws, 
springs,  and  other  small  parts  are  in  place  and  none  are 
loose  inside  the  computer.  Verify  this  by  shaking  the 
computer  gently  and  listening  for  rattling  sounds.  Metallic 
parts  or  metal  flakes  can  cause  electrical  short  circuits.
 Attention:  The  system  board  is  sensitive  to,  and  can  be 
damaged  by,  electrostatic  discharge.  Before  touching  it, 
establish  personal  grounding  by  touching  a  ground  point 
with  one  hand  or  by  using  an  electrostatic  discharge  (ESD) 
strap  (P/N  6405959).
Before
  removing  any  FRU,  turn  off  the  computer, 
unplug  all  power  cords  from  electrical  outlets, 
remove  the  battery  pack,  and  then  disconnect  any 
interconnecting  cables. 
Removing  and  replacing  a  FRU 
ThinkPad  X40  75