Snow Leopard and HP LaserJet 3020 Print Pauses After Upgrade

Symptom:

After upgrading to Snow Leopard we were unable to print any longer using our HP LaserJet 3020 (All in One). The Event Log in the Printer Queue said:

/usr/libexec/cups/backend/usb failed"

When we opened the Terminal and type in a command

/usr/libexec/cups/backend/usb

We saw the following error message:

"Unable to load class driver "/Library/Printers/hp/hpio/HPIOPrinterClassDriver.plugin": No such file or directory"

We Tried To Fix with the Following But Nothing Worked:

• Got the latest 6.0.1 Driver for HP is at http://support.apple.com/downloads/#macosx106
• Check: http://localhost:631/ which is the local CUPS driver admin page.

Solution:

First, from the System Preferences (i.e., control panel) "Printers and Faxes" remove the malfunctioning printer queue for the LaserJet.

Next, Completely Cleanup Driver by doing the following. Please note that this requires a system administration privilege and so I am not going to explain how that is done. If you do not know how to do a "sudo" then you should not do this. Please ask for an assistance from any Unix or Mac OS X knowledgeable person. I suggest that you use Time Machine to get at least one backup of current operating environment.

rm -rf /Library/Application Support/hp folder
rm -rf /Library/Frameworks/HPDeviceModel.framework
rm -rf /Library/Frameworks/HPPml.framework
rm -rf /Library/Frameworks/HPServicesInterface.framework
rm -rf /Library/Frameworks/HPSmartPrint.framework
rm -rf /Library/LaunchAgents/com.hp.launchurlagent.plist
rm -rf /Library/Printers/hp folder
rm -rf /Library/Printers/PPDs/Contents/Resources/hp*.gz
rm -rf /System/Library/Extensions/hp_io_printerclassdriver_enabler.kext

This have completely cleaned up all the HP printer data.

Reboot the system.

Go back to the Printer and Faxes control panel and this time the System will load the latest printer driver from the Internet after you add the printer queue for the Laser Jet, and you should be all set to go.