Contents 
Analyze  hardware  problems  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .1 
Remove  and  replace  procedures  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .2 
Models  270,  800,  and  810  remove  and  replace  procedures  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .2 
Models  270,  800,  and  810  -  Air  moving  device  -  B01  and  B02  .  .  .  .  .  .  .  .  .  .  .  .  .  .3 
Models  270,  800,  and  810  -  Air  moving  device  -  B03  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .3 
Models  270  and  810  -  Cards  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .4 
Models  270,  800,  and  810  -  Cards  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .6 
Models  270,  800,  and  810  -  Control  panel  -  NB1  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .6 
Models  270,  800,  and  810  -  Covers  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .7 
Models  270,  800,  and  810  -  Device  board  -  DB1,  DB2,  and  DB3  .  .  .  .  .  .  .  .  .  .  .  .  .8 
Models  270,  800,  and  810  -  Disk  unit  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .8 
Models  270,  800,  and  810  -  Disk  unit  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .11 
Models  270,  800,  and  810  -  Memory  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .12 
Memory  -  A  through  H  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .12 
Memory  on  the  riser  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .12 
Models  270,  800,  and  810  -  Power  supply  -  P01  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .13 
Models  270,  800,  and  810  -  Power  supply  -  P02  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .13 
Models  270  and  810  -  Processor  -  M02  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .13 
Models  270,  800,  and  810  -  Processor  regulator  -  R01  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .14 
Models  270,  800,  and  810  -  Removable  media  -  D07  and  D08  .  .  .  .  .  .  .  .  .  .  .  .  .  .14 
Laser  safety  information  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .14 
Models  270,  800,  and  810  -  System  unit  backplane  -  MB1  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .15 
Models  270,  800,  and  810  -  Time  of  day  (TOD)  battery  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .16 
Model  820  remove  and  replace  procedures  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .16 
Model  820  -  Air  moving  device  (AMD)  -  B01  through  B04  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .17 
Model  820  -  Cards  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .18 
Model  820  -  Cards  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .19 
Model  820  -  Control  panel  -  NB1  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .20 
Model  820  -  Covers  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .21 
Model  820  -  Device  board  -  DB1  and  DB2  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .21 
Model  820  -  Disk  unit  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .21 
Model  820  -  Disk  unit  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .23 
Model  820  -  Memory  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .24 
Model  820  -  Power  supply  -  P01,  P02,  and  P03  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .25 
Model  820  -  Processor  -  M03  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .25 
Model  820  -  Processor  regulator  -  M03  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .25 
Model  820  -  Removable  media  -  D13  and  D14  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .26 
Laser  safety  information  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .26 
Model  820  -  System  unit  backplane  (MB1)  and  power  distribution  board  (PB1)  .  .  .  .  .  .  .  .26 
Model  820  -  Time  of  day  (TOD)  battery  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .28 
Model  825  remove  and  replace  procedures  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .29 
Model  825  -  Air  moving  device  (AMD)  -  B01;  B02  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .29 
Model  825  -  Cards  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .30 
Model  825  -  Cards  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .32 
Model  825  -  Control  panel  -  NB1  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .33 
Model  825  -  Covers  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .34 
Model  825  -  Device  board  -  DB1  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .34 
Model  825  -  Device  board  -  DB2,  DB3,  and  DB4  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .35 
Model  825  -  Disk  unit  (concurrent)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .35 
Model  825  -  Disk  unit  (dedicated)  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .37 
Model  825  -  HSL  card  -  MB1  and  MB2  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .38 
Model  825  -  Interlock  switch  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .39 
Model  825  -  Memory  -  A  through  H  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .41 
 
©  Copyright  IBM  Corp.  1998,  2002  iii