Unplug the power cord from the back of the printer.
Remove all the ink cartridges.
Wait two minutes.
Plug the power cord into the back of the printer.
Press the On button to turn the printer on.
Re-Install the ink cartridges when prompted.
If this doesnt work then apparently the controller for the inkjets is bad. you would be best served to take it back under warranty or replace the printer
Under Mac OS X 10.6.2, with the latest HP software installed, I cannot open the scanner on my HP...
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Under Mac OS X 10.6.2, with the latest HP software installed, I cannot open the scanner on my HP Photosmart 3310. I get the message "failed to open a session on the device. I have deleted and re-installed the print queue several times.