2 Dell PowerVault 2xxS Storage Systems SCSI Backplane Board Replacement InstructionsSCSI Backplane Replacement OverviewUse the following procedures, in the order listed, to replace the SCSI back-plane board.1. Remove the hard-disk drives.2. Remove the power supplies.3. Remove the cooling fans.4. Remove the enclosure services modules or enclosure services expandermodules.5. Remove the component mounting bracket.6. Remove the dual-bus split backplane module.7. Remove the SCSI backplane board.8. Install the replacement SCSI backplane board.9. Install the dual-bus split backplane module on the replacement SCSI back-plane board.10. Install the component mounting bracket.11. Install the enclosure services or enclosure services expander modules.12. Install the cooling fans.13. Install the power supplies.14. Install the hard-disk drives.Each procedure is described in the following sections.Remove the SCSI Hard-Disk DrivesCAUTION: Note the location of the SCSI hard-disk drives as youremove them from the drive bays. During the installation procedure(found later in this document), you must return the SCSI hard-diskdrives to the same drive bays from which they were removed.To remove the SCSI hard-disk drives from the drive bays, perform the followingsteps.NOTE: The storage system comes with either a silver, swing-out lock bar or ablack, removable lock bar, which secures the hard-disk drives in their drive bayslots.1. Using the key, unlock the keylock.2. For a storage system with the silver, swing-out lock bar, using your finger-tips, tap up on the lock bar. The lock bar easily swings out and down, justbelow the level of the drive bays (see Figure 1).