IBM System Storage Subsystem DS5020 - Manual (Page 138)

When you turn on the power to the storage subsystem, the seven-segment LEDs
show 88 before the boot firmware starts to run. After the boot code starts, - - is
displayed.
When the storage subsystem is operating normally, the numeric display shows the
enclosure identification (enclosure ID) of the storage subsystem.
If an error has occurred and the Needs Attention LED is on, the numeric display
shows diagnostic information. The numeric display indicates the information is
diagnostic by illuminating an LED that appears as a decimal point between the
display numbers. The diagnostic LED tuns off when the numeric display shows the
storage subsystem enclosure ID. The numeric display shows various diagnostic
codes as the enclosures perform the startup process after each power cycle or
reset. After diagnostics are complete, the current storage subsystem enclosure ID is
displayed.
Diagnostic codes in the form of Lx or Hx, where x is a hexadecimal digit, indicate
storage subsystem state information. In general, these codes are displayed only
when the storage subsystem is in a non-operational state. The storage subsystem
might be non-operational due to a configuration problem (such as mismatched
types), or it might be non-operational due to hardware faults. If the storage
subsystem is non-operational due to system configuration, the storage subsystem
Needs Attention LED is off. If the storage subsystem is non-operational due to a
hardware fault, the storage subsystem Needs Attention LED is on. The definitions
for Lx diagnostic codes are listed in Table 17.
Table 17. Numeric display diagnostic codes
Value Controller State Description
L0 Suspended Mismatched controller board
ID
L1 Suspended Missing interconnect canister
L2 Suspended Persistent memory errors
L3 Suspended Persistent hardware errors
L4 Suspended Persistent data protection
errors
L5 Suspended ACS failure
L6 Suspended Unsupported host card
L7 Suspended Submodel identifier not set or
mismatched
L8 Suspended Memory configuration error
L9 Suspended Link speed mismatch
Seven-segment
display Diagnostic
LED
Figure 72. Numeric display LEDs
108 IBM System Storage DS5020 Storage Subsystem: Installation, User’s, and Maintenance Guide