User's Manual
Memory  problems 
v  Follow  the  suggested  actions  in  the  order  in  which  they  are  listed  in  the  Action  column  until  the  problem 
is  solved. 
v  See  the  parts  listing  in  the  Problem  Determination  and  Service  Guide  to  determine  which  components  are 
customer  replaceable  units  (CRU)  and  which  components  are  field  replaceable  units  (FRU). 
v  If  an  action  step  is  preceded  by  “(Trained  service  technician  only),”  that  step  must  be  performed  only  by  a 
trained  service  technician. 
Symptom  Action 
The  amount  of  system  memory 
that  is  displayed  is  less  than  the 
amount  of  installed  physical 
memory. 
1.  Make  sure  that: 
v  No  error  LEDs  are  lit  on  the  front-panel  assembly  or  on  the  system  board. 
v  Memory  mirroring  does  not  account  for  the  discrepancy. 
v  The  memory  modules  are  seated  correctly. 
v  You  have  installed  the  correct  type  of  memory. 
v  If  you  changed  the  memory,  you  updated  the  memory  configuration  in  the 
Configuration/Setup  Utility  program. 
v  All  DIMMs  are  enabled.  The  server  might  have  automatically  disabled  a 
DIMM  when  it  detected  a  problem,  or  a  DIMM  might  have  been  manually 
disabled.
2.
  Check  the  POST  error  log  for  error  message  289: 
v  If  a  DIMM  was  disabled  by  a  system-management  interrupt  (SMI),  replace 
the  DIMM. 
v  If  a  DIMM  was  disabled  by  the  user  or  by  POST,  run  the  Configuration/Setup 
Utility  program  and  enable  the  DIMM.
3.
  Run  memory  diagnostics  (see  “Running  the  diagnostic  programs”  in  the 
Problem  Determination  and  Service  Guide  on  the  IBM  xSeries  Documentation 
CD). 
4.  Make  sure  that  there  is  no  memory  mismatch  when  the  server  is  over  the 
minimum  memory  configuration  (one  512  MB  DIMM)  and  that  you  have 
installed  the  correct  number  of  DIMMs  (see  the  User’s  Guide  on  the  IBM 
xSeries  Documentation  CD  for  information  about  installing  optional  memory 
modules). 
5.  Reseat  the  DIMMs. 
6.  Replace  the  following  components  one  at  a  time,  in  the  order  shown,  restarting 
the  server  each  time: 
a.  DIMMs 
b.  (Trained  service  technician  only)  System  board
68  xSeries  206m  Types  8485  and  8490:  Installation  Guide










