HP 310X - Manual (Page 169)

12 LAN Error: NO LINKBEAT
for HP Jetdirect 175x external print server/Internet connector for USB
and HP Jetdirect 310x external print server/Internet connector for
USB
When the print server is connected to a 10/100 Base-TX port, this
message is displayed if the Link Beat signal is not sensed.
Check the network cable, and verify that the hub/switch/router is
providing Link Beat.
For help in correcting this error, please check your print server
documentation or contact HP Jetdirect technical support. Click on the
button below for information on contacting HP.
©2000, 2001 Hewlett-Packard Company