Dell PowerVault 720N Installation And Troubleshooting Manual page 54

3-2 Dell PowerVault 720N, 740N, and 760N Installation and Troubleshooting Guide
The LEDs and LCD are controlled by a built-in environmental controller sensor on the
system board that functions as the interface between them and the processor. This
controller/sensor monitors environmental conditions, such as the temperature and fan
status, and displays signals on the LEDs and messages on the LCD.
Should any corrective action be required, the LCD displays a message. Refer to "LCD
Messages" to determine what corrective action is required for a particular message.
Figure 3-1 shows the LEDs on the front panel.
Activity LED
Status LED
Power LED