Dell Precision 390 Quick Reference Manual page 20

7 USB 2.0 connectors (2)
8 Dell badge rotation
notch
9 power button
10 power light
11 microphone connector
12 headphone connector
13 diagnostic lights (4)
14 network link light
20
Quick Reference Guide
Use the USB connectors on the front of your computer for devices that you
connect occasionally, such as flash memory keys or cameras, or for bootable USB
devices (see "System Setup" in your User's Guide for more information on booting
to a USB device).
It is recommended that you use the back USB connectors for devices that typically
remain connected, such as printers and keyboards.
To rotate the badge, place your fingers around the outside of the badge, press in,
and turn the badge. You can also rotate the badge by using the slot provided near
the bottom of the badge.
Press this button to turn the computer on.
NOTE:
The power button can also be used to wake the system or to place it into
a power-saving mode. See "Power Management" in the User's Guide for more
information.
NOTICE:
To avoid losing data, do not use the power button to turn the
computer off. Instead, perform an operating system shutdown.
The power light illuminates and blinks or remains solid to indicate different states:
• No light — The computer is turned off.
• Steady green — The computer is in a normal operating state.
• Blinking green — The computer is in a power-saving mode.
• Blinking or solid amber — See "Power Problems" in the User's Guide.
To exit from a power-saving mode, press the power button or use the keyboard or
the mouse if it is configured as a wake device in the Windows Device Manager. For
more information about sleep modes and exiting from a power-saving mode, see
"Power Management" in the User's Guide.
See "Diagnostic Lights" on page 37 for a description of light codes that can help
you troubleshoot problems with your computer.
Use the microphone connector to attach a personal computer microphone for
voice or musical input into a sound or telephony program.
Use the headphone connector to attach headphones and most kinds of speakers.
Use the lights to help you troubleshoot a computer problem based on the
diagnostic code. For more information, see "Diagnostic Lights" on page 37.
The network light is on when the computer sends or receives data over a network
connection. The light might also be on when a network device is establishing a
network connection.