HP 310X - Manual (Page 148)

USB light OFF
for HP Jetdirect 175x external print server/Internet connector for USB
and HP Jetdirect 310x external print server/Internet connector for
USB
If the USB light is OFF, it means that the print server’s USB
connection is not operational. This is OK before the print server
finishes starting up (whether or not a USB cable is attached). If the
light remains OFF after startup, then the print server may be faulty.
Please restart the print server by detaching the power cable and
re-attaching it. Wait for the power/status light to stop blinking
(when the self-test finishes).
Is the USB light now ON solid green?
If yes, click on the Yes button to return to the Troubleshooting
Overview page and continue with the next step of the troubleshooting
procedure.
If no, your print server has a problem that requires assistance from HP
Jetdirect technical support; click on the No button for information on
contacting HP.
©2000, 2001 Hewlett-Packard Company