Chapter 9 Maintaining the Crossbar Units 179
9.1 Configurationof the Crossbar Units 179
9.2 Before Maintaining a Crossbar Unit 180
9.2.1 Types of maintenance 180
9.2.2 Maintenanceflow 181
9.3 Enablingthe Removal of a Crossbar Unit 181
9.3.1 Active/Cold maintenance 182
9.3.2 Inactive/Cold maintenance 182
9.3.3 System-stopped maintenance 183
9.4 Removinga Crossbar Unit 184
9.4.1 Accessing a crossbar unit 184
9.4.2 Removinga crossbar unit 184
9.5 Installing a Crossbar Unit 186
9.5.1 Installing a crossbar unit 187
9.5.2 Restoring the chassis 187
9.6 Restoringthe System 187
9.6.1 Active/Cold maintenance 187
9.6.2 Inactive/Cold maintenance 188
9.6.3 System-stopped maintenance 190
Chapter10 Maintaining the Power Supply Units 191
10.1 Configurationof the Power Supply Units 191
10.2 BeforeMaintaining a Power Supply Unit 192
10.2.1 Types of maintenance 192
10.2.2 Maintenanceflow 193
10.2.3 Precautions for replacement 193
10.3 Enablingthe Removal of a Power Supply Unit 194
10.3.1 Active/Hotmaintenance 194
10.3.2 Active/Coldmaintenance 195
10.3.3 Inactive/Hotmaintenance 196
10.3.4 Inactive/Coldmaintenance 197
10.3.5 System-stopped maintenance 198
Contents vii