Hardware Overview of the Modem Router
AC1600 WiFi VDSL/ADSL Modem Router Model D6400
The following table describes the LEDs from right to left and their behavior. For information
about how to troubleshoot with the LEDs, see Troubleshoot with the LEDs on page 274.
Table 1. LED descriptions
LED Icon Description
Power • Solid green. The power is on and the modem router is functioning normally.
• Solid amber. The modem router is booting. After about one minute and 10 seconds,
the Power LED turns solid green.
• Blinking amber. The Reset button on the back panel is pressed.
• Off. The modem router is not receiving power.
DSL • Solid green. The modem router is providing a DSL connection. In technical terms,
the DSL port is synchronized with an ISP’s network-access device.
• Blinking green. The modem router is negotiating the best possible speed on the
• Off. The modem router is not negotiating the speed on the DSL line and is not
providing a DSL connection.
Internet • Solid green. The modem router is connected to the Internet.
• Solid amber. The modem router failed to connect to the Internet. For more
information, see Troubleshoot the Internet Connection on page 276.
• Alternating green and amber. The traffic meter is enabled and the traffic limit was
• Off. The modem router did not detect an Internet connection or functions in bridge
mode (that is, an external device handles the IP connection).
WiFi • Solid blue. One or both WiFi radios are enabled and the modem router is providing
• Blinking blue. WPS (Wi-Fi Protected Setup) is active.
• Off. Both WiFi radios are disabled and the modem router is not providing WiFi
connectivity. You can still plug an Ethernet cable into one of the LAN ports to get
USB • Solid blue. A USB device is connected to a USB port and is ready.
• Blinking blue. A USB device is connected to a USB port and is trying to connect.
• Off. No USB device is connected or someone clicked the Safely Remove Hardware
button, and it is now safe to remove the attached USB device.
If the LED does not turn green, a power-on self-test (POST) failure occurred or the
modem router is malfunctioning. For more information, see Power LED Remains Solid
Amber on page 274.
When you release the Reset button, the Power LED blinks amber three times and
then turns green as the modem router resets to the factory defaults.