HP 175X, 310X manual USB Light, Light Behavior, Description

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	Description
Behavior
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	USB is enabled and ready for use. This begins before
green	the USB cable is connected.
Blinking	Software fault occurred for the firmware. There is a
(green)	valid USB device and connections, but the device is
	not supported. Make sure the attached device is a
	printer.
Blinking	Might be a hardware fault (for example, a
(amber)	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: