HP A3550A - High Availability Disk Arrays Model 20 Storage Enclosure User Manual page 253

Disk Array Front-View LEDs
Front of storage system
System System
power LED service LED
(green)
(amber)
A0 B0 C0 D0
A1 B1 C1 D1
A2 B2 C2 D2
Figure 6-2 Front LED Locations
E0 A3 B3 C3 D3 E3
E1 A4 B4 C4 D4 E4
E2 A5 B5 C5 D5 E5
Disk module LEDs
Ready LED (green)
Busy LED (green)
Fault LED (amber)
Disk Array Chassis 6-5