HP 310X - Manual (Page 133)

Light Behavior Description
Off No network connection.
On solid green Network connection is established at 10 Mb/s
or at 100Mb/s.
USB Light
Light
Behavior Description
Off USB is not operational. This is OK before the print
server finishes starting up. After startup completes,
this could indicate a faulty print server.
On solid
green USB is enabled and ready for use. This begins before
the USB cable is connected.
Blinking
(green) Software fault occurred for the firmware. There is a
valid USB device and connections, but the device is
not supported. Make sure the attached device is a
printer.
Blinking
(amber) Might be a hardware fault (for example, a
short-circuit, faulty cable, or a printer drawing too
much power).
To verify, disconnect the USB cable at the print
server. Switch on the printer if it is off. Power cycle
the print server (unplug it and plug it back in). Then
reconnect the USB cable. If the USB light is now
green and steady, then no problem remains.
Otherwise, if the USB light is still blinking amber,
then there may be a faulty component. Try these steps
to determine which component might be causing the
problem: