The main reasons why an HP printer may not be printing include:
- Loss of wireless connection or faulty connection to the computer or network.
- Low or empty ink cartridges.
- Paper jams or no paper in the tray.
- Print jobs stuck in the print queue.
- Outdated or missing printer drivers.
- Clogged print heads preventing ink flow.
- Incorrect printer settings, such as wrong default printer.
To fix the issue, one should check the printer's wireless or wired connection status, verify ink and paper levels, clear any paper jams, check and clear print jobs in the queue, update or reinstall printer drivers, clean the print heads, and ensure the printer is set as the default device on the computer. Performing a power reset may also help resolve software glitches.