Turn off the HP LaserJet 2840.
Press and hold down the "Enter" and "*" keys on the printer's control panel, and turn the printer back on.
Hold the "Enter" and "*" keys until you see the "Permanent Storage Init" message on the device control panel. Release the two keys to perform the NVRAM initialization. The NVRAM initialization takes just a few seconds, and the "Permanent Storage Init" message remains on the printer's display until the initialization is complete.
Ensure that the "Ready" message on the printer's control panel is visible. You can now connect the printer to your computer and print your documents. If the "Ready" message is not displayed and your printer is still stuck in a loop, turn off the printer and contact HP customer support (see Resources).
- To reset an HP 2840 from your computer, open the HP Toolbox program, click "Device Settings," click "Service," click "Restore" in the Resets section and then click "OK" to confirm the action and restore the printer to its factory defaults.