General  descriptions 
This  chapter  includes  descriptions  for  any  ThinkPad  model 
that  has  the  PC-Doctor
®
 
DOS  diagnostics  program.  Some 
descriptions  might  not  apply  to  your  particular  computer. 
Read  this  first 
Before  you  go  to  the  checkout  guide,  be  sure  to  read  this 
section. 
 
 
Important  notes 
v  Only  certified  trained  personnel  should 
service  the  computer. 
v  Read  the  entire  FRU  removal  and  replacement 
page  before  replacing  any  FRU. 
v  Use  new  nylon-coated  screws  when  you 
replace  FRUs. 
v  Be  extremely  careful  during  such  write 
operations  as  copying,  saving,  or  formatting. 
Drives  in  the  computer  that  you  are  servicing 
sequence  might  have  been  altered.  If  you  select 
an  incorrect  drive,  data  or  programs  might  be 
overwritten. 
v  Replace  FRUs  only  for  the  correct  model. 
When  you  replace  a  FRU,  make  sure  the  model 
of  the  machine  and  the  FRU  part  number  are 
correct  by  referring  to  the  FRU  parts  list. 
v  A  FRU  should  not  be  replaced  because  of  a 
single,  unreproducible  failure.  Single  failures 
can  occur  for  a  variety  of  reasons  that  have 
nothing  to  do  with  a  hardware  defect,  such  as 
cosmic  radiation,  electrostatic  discharge,  or 
software  errors.  Consider  replacing  a  FRU  only 
when  a  problem  recurs.  If  you  suspect  that  a 
FRU  is  defective,  clear  the  error  log  and  run  the 
test  again.  If  the  error  does  not  recur,  do  not 
replace  the  FRU. 
v  Be  careful  not  to  replace  a  nondefective  FRU.
What  to  do  first 
When  you  do  return  a  FRU,  you  must  include  the  following 
information  in  the  parts  exchange  form  or  parts  return  form 
that  you  attach  to  it: 
__  1.  Name  and  phone  number  of  servicer 
__  2.  Date  of  service 
__  3.  Date  on  which  the  machine  failed 
 
©  Copyright  IBM  Corp.  2005  29