Solution 1 (from HP):
- Without turning off the printer, disconnect the USB cable from the rear of it.
- Remove the cartridges from the printer.
- Wait for the 'Insert Cartridges' message to display on the control panel.
- Disconnect the power cord from the back of the printer.
- Wait a minute.
- Reconnect the power cord. If the printer does not automatically turn on, press the Power button.
- Reinsert the cartridges, and then close any open doors on the printer.
- If you receive a prompt to print a calibration page, do so.
- Reconnect the USB cable to the rear of the printer, and then try printing again.
Solution 2: It could be a a print head issue.
- Open the printer and wait for the carriage to slide over
- Remove the ink cartridges from the print head.
- Use cotton swabs dipped in hot water to thoroughly clean the print head and each ink cartridge.
- Repeat this until there is no ink residue coming off on the cotton swab.
- Once finished, allow to dry and replace the cartridges
- Try to print something now
- One of the ink cartridges is defective. Replace it.