After bouncing back and forth between HP and Apple for more than a year, I was about to throw the printer out. My problem started when I installed 10.8 and tried to use the printer on a WPA2 secure wireless network.
Here is the answer that worked for me:
On your Mac:
- Delete the HP C309a from the Printers list ( System Preferences > Printers & Scanners )
- Turn ON Internet Sharing from WiFi to Computer Using Bluetooth PAN ( System Preferences > Sharing ) - be aware that this opens your computer up to connections from any device
- Add the the HP C309a to the Printers list ( should appear as Kind > "bluetooth" )
At the C 309a Printer:
- Press the Setup button
- Select "Network" from Setup Menu
- Run the "Wireless Network Setup Wizard" and follow the prompts (if you've gotten this far, you've already won)
On your Mac:
- Delete the HP C309a from the Printers list ( System Preferences > Printers & Scanners )
- Add the the HP C309a to the Printers list ( should appear as Kind > "Bonjour" )
- Turn OFF Internet Sharing from WiFi to Computer Using Bluetooth PAN ( System Preferences > Sharing ) - this closes the any device access from above
Once I did the above, everything on the printer worked including the scanner. This is verified to work on OS X 10.8 and
OS X 10.9 Developer Preview 8 (13A584).