HP 310X - Manual (Page 134)

Detach the USB cable and power cycle the print
server (unplug it and plug it back in). If the
USB LED is green and steady, then the print
server is OK. If it is blinking amber, then the
print server is faulty. ●
Try reconnecting the USB cable to the print
server only, and power cycle the print server
(unplug it and plug it back in). If the USB LED
is green and steady, then the cable is also OK. If
it is blinking amber, then the cable may be
faulty. ●
Power cycle the printer and reconnect the USB
cable to the printer. If the USB LED is green
and steady, then the printer is also OK. If it is
blinking amber, then the printer may be faulty. ●
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