@Lisa114
You did not include the Operating System you are using and in the case of HP Smart, there are big differences in printing with HP Smart Application on a mobile device as compared to printing with HP Smart in Windows 10.
Print from your Android, iOS, or Amazon Fire device with the HP Mobile printing app.
If you are trying to print from your mobile device (iPad / phone, for example), then you can try either resetting the application on that device or perhaps uninstalling the application and then reloading it. This will likely require that you know your login credentials for your network (WiFi network SSID (name) and network login password for that WiFi network).
Additional help is available in the FAQ section of the "Using the HP Smart App" document.
HP Smart for Windows 10
Help for HP Smart for Windows (includes a link to the store)
Removing the application and reinstalling it may help.
HP Smart Application in Windows 10 can be uninstalled (how-to in document).
After you remove the application, Restart the computer and log in.
Open the Windows Store, find the application, and install (how-to in document).
NOTES:
- You might need to check / reset / adjust your WiFi network credentials (SSID Network name and network password).
- Make sure you are connecting the printer to the same network as you are using for the rest of your network (computer, router, other devices).
References - More information and places to look for solutions
For Windows - HP Deskjet 2540 All-in-One Printer series Full Feature Software and Drivers
Troubleshooting
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Find Your Wireless WEP, WPA, WPA2 Password
No Connection after Router or Wi-Fi Settings Change
Printer Does Not Maintain Wi-Fi Connection
A 'No AirPrint Printers Found' Message Displays (iOS)
A 'Printer Isn't Available' Message Displays (Android)
How to
Featured content for selected topic includes and is not limited to:
Printing from an iPhone, iPad, or iPod Touch
Using the HP Smart App (Android, Apple iOS)
Printing from Android Smartphones or Tablets
Mobile Printing Solutions Compatible with HP Printers
Still need help? Want more information? Search for solutions...
Reference and Resources – Places to find (more) help and learn about your Printer
Printer Homepage – “Things that are your printer”
NOTE: Content depends on device type
Drivers / Software / Firmware Updates, How-to Videos, Bulletins/Notices, Lots of How-to Documents, Troubleshooting, User Guides, Product Information, more
HP Deskjet 2540 All-in-One Printer series
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