This is can be the result of the network blocking traffic accross port 515 due to Macs connected wirelessly over the network.
Since the driver uses Line Printer Daemon (LPD) to connect to the printer, and LPD traffic uses port 515, in this situation the print driver will not be able to establish a connection to the printer.
To get around this, remove the printer and re-add it using the HP Jet Direct protocol. HP Jet Direct is the Mac equivalent of the Microsoft Windows RAW protocol. It uses port 9100 to establish a connection to the printer.
- Select the Apple logo in the upper left-hand corner of the screen.
- Select System Preferences.
- Select the Printers and Scanners icon.
- Select the printer from the list on the left.
- Select the minus (-) symbol to remove it.
- Select the plus (+) symbol to add a printer.
- Select IP at the top of the add printer window.
- Find and enter the IP address of the printer in the IP Address / Hostname Field.
- Change the protcol from 'LPD" to HP Jet Direct.
- Leave the Queue field blank.
- Give the printer a name. For example: Xerox Color C60/C70.
- Select the Select Software option from the Use dropdown menu.
- Select the Color C60/C70 EX-i Fiery driver from the list.
- Select Add. The printer will now show up in the list of available printers.
NOTE: You may need to contact your Network Administrator for network related assistance.