What causes HP printers to go offline?
If you mean that Windows is reporting the printer as offline, it is just saying that it receives no status updates from the printer. This is a Windows/printer port communication issue and is rarely related to the printer it self.
If the machine itself loses network connectivity, you should troubleshoot the issue exactly like when any other network equipment loses connectivity:
Ping the printer from a PC to verify that it actually is offline.
I would prescribe you either reinstall the driver or go in to the Printer Properties - > Ports and set up another TCP/IP port with the IP address of the printer.
How to Get HP Printer Online?
There could be several factors responsible for the occurrence of HP printer offline error, but the below-given steps will help you resolve it effortlessly.
On the off chance that the issue holds on, something is likely blocking traffic on port 9100 on your system. This is regularly the situation if the PC is associated with a remote system and the printer is on a cabled system. Once in a while this can be comprehended in the access point/switch setup.
which will help you avoid “Printer says Offline” errors for a long run.
On the off chance that you can't unravel the issue, you can work around it by choosing the recently made TCP/IP port, tap the "Arrange Port" catch and from that point incapacitate the "SNMP Status Enable" checkbox. This will make Windows never again endeavor to screen the status of the printer and it ought to therefor never report the printer as disconnected.
If you are fed up trying all troubleshooting methods but unable to bring your printer to online mode, you can directly contact HP experts via HP printer support number and discuss “why is my HP printer offline?” and other related concerns. The technicians will remotely access your device and resolve the errors or whatever the cause of errors. In this way, you can fetch a guaranteed solution for your dilemma. The best part is you don’t need to move out of your place to avail technical support for your HP printer