my computer under printers & devices always says offline--I can't get it change to ready to print

[Delro72]

I have a wireless HP 5510 printer networked with a router connection.  Sometimes I can't print because it says that I am offline and I can't get it to ready.  Help! 

[A4Apollo]

Hey there! @Delro72, Thanks for stopping by HP forums!

I understand you are getting printer offline error on your PC.

Don't worry I'd like to help you out.

Did you make any changes to your printer?

How is the printer connected wired or wireless?

Please try the steps recommended below.

Resetting the printer can help restore a connection to the computer.
If the printer is off, turn on the printer, and then check the status of the printer.
If the printer starts printing jobs from the print queue, your printer is clearing out queued print jobs and is online. You can stop troubleshooting.
If the printer goes to an idle state after its startup routine, it might be online.
If the computer still shows the printer as offline, continue using these steps.
With the printer turned on, disconnect the power cord from the printer.
Unplug the printer power cord from the wall outlet.
Wait at least 60 seconds. Restart the computer while you are waiting.
Plug the power cord back into the wall outlet.
Reconnect the power cord to the rear of the printer.
If the printer does not turn on by itself, press the Power button to turn it on.
Make sure the printer is connected to the computer or the network.
Wireless network connection: On the printer, open the Wireless network or Settings menu to make sure the wireless signal is turned on. Make sure the light next to the Wireless icon is on and steady.
Wired network connection: Make sure the cable is connected to the printer Ethernet port and to an available port on the router. The green link light should be steady, and the orange activity light should blink.
USB connection: Make sure the cable is securely connected to the printer and to a working USB port on the computer.
Try to print.
If you can print, the printer is online again. Continue to the next step if the printer goes offline again when printing later.

Refer this article to further troubleshoot printer offline issues.

Let me know how it goes!

Take Care! 🙂