Light  path  diagnostics 
The  following  illustration  shows  the  remind  button  and  the  LEDs  on  the  light  path 
diagnostics  panel.  The  light  path  diagnostics  panel  is  inside  the  server  under  the 
left-side  cover,  and  the  error  LEDs  are  also  visible  through  the  left-side  cover. 
CPU
VRMS_ERR
MEMORY
DASD/
RAID
NMI
SP BUS
FAN
POWER
SUPPLY
PCI
BUS
2
1
CONFIG
TEMP
REMIND
SEE INSIDE COVER FOR MORE SERVICE INFORMATION
 
 
Press  the  remind  button  on  the  light  path  diagnostics  panel  to  acknowledge  that  an 
error  has  occurred  but  indicate  that  you  will  not  take  immediate  action.  When  you 
press  the  remind  button,  the  system-error  LED  flashes  every  2  seconds  until  the 
error  is  corrected.  If  another  error  occurs,  the  system-error  LED  stops  flashing  and 
is  lit  again. 
For  more  information  about  light  path  diagnostics,  see  the  Problem  Determination 
and  Service  Guide  on  the  IBM  System  x  Documentation  CD. 
Diagnosing  problems  using  light  path  diagnostics 
LEDs  in  three  locations  on  the  server  are  available  to  help  you  diagnose  problems 
that  might  occur  during  installation.  Use  them  in  the  following  order: 
1.  LEDs  on  the  front  of  the  server:  Look  at  the  front  of  the  server.  If  a  system 
error  has  occurred,  the  system-error  LED  on  the  front  of  the  server  is  lit. 
2.  LEDs  on  the  left-side  cover:  There  are  13  LEDs  and  a  system  service  label 
on  the  left-side  cover.  Note  the  lit  LEDs  and  follow  the  instructions  on  the 
system  service  label. 
3.  LEDs  on  the  system  board:  To   identify  the  component  that  is  causing  the 
error,  note  the  lit  LED  next  to  the  component.
 
 
90  IBM  System  x3500  Type  7977:  Installation  Guide