The troubleshooting steps in the document here may help resolve your Deskjet Ink Advantage 2640 going through the motions of printing but the pages are blank.
It is possible both cartridges would appear to be dried out if the printer was turned off from an external switch such as an outlet switch or power director. It is also possible that if the printer is near a window and exposed to direct sunlight that the printer cartridges could dry out. If either is the case and you do not have replacement cartridges handy I would suggest the following: get two clean coffee cups and put 1" of hot (but not boiling) water in each. Now put the cartridges nose down in the water (one in each cup) for ten minutes. After ten minutes remove the cartridges and dry the electrical contacts with a lint free wipe ( a clean coffee filter works well for this). Put the cartridges back in the printer and run a cleaning cycle as shown in the link above.
Bob Headrick, HP ExpertI am not an employee of HP, I am a volunteer posting here on my own time.
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