If you want to “Diagnose HP Printer Problems” when it's offline, then unplug the printer from the laptop then plug it in once more, and power it on. Connect the printer lower back to the power cable however, don’t switch it on. Now connect the printer again to the pc and power it on. The computer will stumble on the printer and may be ready to use. If you still face issues then visit the begin menu and click the manage panel, pick out ‘Printer & faxes’ there, and properly click on on the printer and select use printer online.