4.  Remove  the  disk  units  from  the  system.  Identify  each  disk  unit  with  a  disk  unit  board  location  and  slot 
location. 
 
5.  Remove  the  four  short  screws  on  the  perimeter  of  the  disk  unit  board/cage  aAssembly  and  the  two 
longer  screws  located  inside  the  assembly. 
 
6.  Partially  remove  the  disk  unit  board/cage  assembly. 
 
7.  Caution  while  performing  this  step:  The  disk  unit  board/cage  assembly  power  connector  plugs 
directly  into  the  power  connector  bracket  assembly.  Viewing  the  connector  from  the  right  side  of  the 
system;  pull  on  the  board/cage  assembly  just  until  the  connector  disengages.  Do  NOT  attempt  to 
remove  the  board/cage  assembly  from  the  system  because  the  SCSI  cable  is  attached  on  the  left 
side  of  the  board/cage  assembly  and  it  will  be  damaged. 
 
8.  Remove  the  removable  media  units  from  the  system.  Identify  each  removable  media  unit  with  slot 
location. 
 
9.  Remove  the  two  short  screws  on  the  perimeter  of  the  removable  media  unit  board/cage  assembly, 
and  the  two  longer  screws  located  inside  the  assembly. 
10.  Remove  the  removable  media  board/cage  assembly  from  the  system.  The  removable  media 
board/cage  assembly  power  and  SCSI  cables  must  be  removed  from  the  back  side  of  the  assembly. 
Viewing  the  assembly  from  the  right  side  of  the  system;  pull  on  the  on  the  board/cage  assembly  just 
until  you  can  unplug  these  cables;  then  remove  the  assembly  from  the  system. 
11.  Remove  the  top  air  moving  device  (AMD)  assembly. 
12.  Remove  the  AMD  power  cable  plug  from  the  power  cable  harness  assembly  connector. 
13.  Remove  the  power  cable  harness  assembly  AMD  connector  from  the  inner  frame  wall,  by  squeezing 
the  tabs  located  on  the  connector. 
14.  Remove  the  four  screws  from  the  power  cable  retaining  bracket,  located  on  the  right  side  of  the 
system. 
15.  Remove  the  three  screws  from  each  of  the  power  supply  connectors.  Slide  the  power  supply 
connectors  down  to  remove  it  from  the  system  frame. 
16.  Remove  the  five  power  cable  connectors  from  the  backplane  assembly;  write  down  their  locations. 
17.  Remove  the  Interlock  switch  assembly  plug  from  the  power  cable  harness  assembly  connector. 
18.  Remove  the  power  cable  harness  assembly  from  the  system. 
19.  Reverse  these  steps  to  install  the  replacement  power  cable  harness. 
20.  Power  on  the  system.  It  should  IPL  without  an  Interlock  system  reference  code  (SRC).
This
  ends  the  procedure.
Model  825  -  Power  supply  P01  and  P02 
For  use  by  authorized  service  providers. 
Use  this  procedure  to  remove  or  replace  the  power  supply  P01  and  P02  on  a  Model  825. 
Note:  Two  powered  on/rotating  air  moving  devices  (excluding  the  air  moving  devices  (AMDs)  mounted  on 
the  power  supplies),  and  two  power  supplies  MUST  be  installed  to  perform  this  procedure  concurrently. 
To  remove  or  replace  the  power  supply  P01  or  P02: 
1.  Are  there  two  powered  on/rotating  AMDs  and  two  power  supplies  installed  in  the  system  unit? 
v  Yes:  Continue  with  the  next  step. 
v  No:  Perform  the  following: 
a.  Power  down  the  system  unit.  See  Power  on/off  the  system  and  logical  partitions. 
b.  Remove  the  power  cord  from  the  rear  of  the  system  unit,  and  continue  with  the  next  step.
2.
  Remove  the  back  side  cover,  see  Model  825  -  Covers. 
3.  Remove  the  power  cord  from  the  power  supply  to  be  replaced. 
4.  Pull  out  the  power  supply  handle  release  button. 
 
42  Hardware  (Remove  and  Replace;  Part  Locations  and  Listings)