To keep an HP printer from going offline, move it closer to the router when connected to a wireless network. Alternatively, use a network cable that fits firmly into the printer and computer for a cable connection, give the printer a static IP address or assign the correct port number.
To set a static IP address, print the IP address information from Network Configuration Page on the printer. Type the address on the computer’s browser, and hit Enter. Select the Networking tab, and then the Wireless option. Next, select the IPv4 tab. Change the last set of numbers in the IP address, and set the Subnet and DNS entries to match the Network Configuration Page values.
Click Apply to effect the changes. Shut down the printer and router. Restart the router and then the printer. Check if printing is restored. If not, add the printer again using the new IP address.
To assign a new port, check the port number from another computer that prints. Open the computer, and click on Start. From there, click on Control Panel, and then choose View Devices and Printers. Right-click on the printer, and select Properties. Hit the Ports tab, and then click Add Port, and select Standard TCP/IP Port. Click New Port, and follow the screen instructions to set a new port.