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  server  does  not  turn  off. 
1.  Turn  off  the  server  by  pressing  the  power-control  button  for  5  seconds. 
2.  Restart  the  server. 
3.  If  the  server  fails  POST  and  the  power-control  button  does  not  work,  disconnect 
the  power  cord  for  20  seconds;  then,  reconnect  the  power  cord  and  restart  the 
server. 
 
Attention:  In  a  dc  power  environment,  only  trained  service  personnel  other 
than  IBM  service  technicians  are  authorized  to  connect  or  disconnect  power  to 
the  dc  power  supply.  See  the  documentation  that  comes  with  each  dc  power 
supply. 
4.  If  the  problem  remains,  suspect  the  system  board. 
The  OVER  SPEC  LED  on  the 
light  path  diagnostics  panel  is 
lit,  and  the  one  of  the  power 
channel  LEDs  on  the  system 
board  is  lit. 
See  the  power  troubleshooting  table  in  the  Problem  Determination  and  Service 
Guide  or  call  for  service. 
The  server  unexpectedly  shuts 
down,  and  the  LEDs  on  the 
operator  information  panel  are 
not  lit. 
See  “Solving  undetermined  problems”  in  the  Problem  Determination  and  Service 
Guide.
 
Serial  port  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  number  of  serial  ports  that 
are  identified  by  the  operating 
system  is  less  than  the  number 
of  installed  serial  ports. 
1.  Make  sure  that: 
v  Each  port  is  assigned  a  unique  address  in  the  Configuration/Setup  Utility 
program  and  none  of  the  serial  ports  is  disabled. 
v  The  serial-port  adapter  (if  one  is  present)  is  seated  correctly.
2.
  Reseat  the  serial  port  adapter,  if  one  is  present. 
3.  Replace  the  serial  port  adapter,  if  one  is  present. 
 
72  IBM  System  x3650  Type  7979:  Installation  Guide