IBM BladeCenter S Installation And User Manual page 23

You can turn off the information LED through the Web interface or
the IBM Director console.
System error
Lit (amber). A system error has occurred, such as a module failure
or a system error in a blade server. An LED on the failing
component is also lit to assist in isolating the error.
DVD drive activity LED
Lit (green). The drive is in use.
DVD drive eject button
Press this button to open the DVD drive.
USB ports
Connect USB devices to these ports.
Battery backup unit:
Battery backup units provide backup for SAS RAID controller modules cache.
Battery backup units are installed in the battery backup unit bays located in the
media tray when you install SAS RAID controller modules. The battery backup
unit in battery backup bay 1 provides backup support for the SAS RAID controller
module in I/O module bay 3; the battery backup unit in battery backup bay 2
provides backup support for the SAS RAID controller module in I/O module bay
4.
Note: Both battery backup units are required if you install SAS RAID controller
modules.
Controls and indicators
The battery backup unit provides the following indicators:
Power Lit (green). Power is being supplied to the battery backup unit.
Charging
Lit (green). The battery backup unit is being charged.
Fault Lit (amber). The battery backup unit has a failure. If the Fault LED is lit,
replace the battery backup unit.
11
Chapter 1. Introduction