Hi @Darlene77,
Welcome to the HP Support Community!
Thanks for posting your query! We're here to help you get back up and running.
I understand you are facing printer offline issue on your printer and you need assistance to fix it.
Not to worry I'll do everything I can to help get this sorted for you.
Let us update the firmware of your printer to resolve the offline issue.
Make sure the printer is turned on and connected to your computer.
Click on the link below to download the firmware for your printer model.
HP DeskJet Plus 4100 All-in-One series Software and Driver Details
Update the Firmware via Wi-Fi Direct or USB Cable
Connect the computer to your printer's Wi-Fi Direct using the following graphic.
Note: For the network security key, use the Wi-Fi Direct password available in the Printer Information Page.
Execute the downloaded HP Printer Update file. On the HP Printer Update screen, check the status of your printer.
If your network printer does not display, use a USB cable (if available or crew USB cable to customer) to temporarily connect your printer to the computer. Wait for 20 seconds, and then click Refresh.
If the status is Ready, select the check box next to the serial number, and then click Update.
CAUTION: To avoid damaging your printer, do not turn off the printer during a firmware update.
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