Remember no 3G...
Also try rebooting device.
Install an app for iOS called "Bonjour Browser". https://itunes.apple.com/us/app/discovery-bonjour-browser/id305441017?mt=8
It's free and VERY useful. I'd recommend you install it on your iOS devices. It's a tool that browses for Bonjour services on the network. If Bonjour Browser doesn't see the printers, then there is a problem with the network.
We advertise as "IPP (Internet Printing Protocol)"...that's how it shows up on Bonjour Browser. Touch that and you should see all the FingerPrint enabled printers on your network.
First, try rebooting device.
Then try updating your OS for your iOS.
There are a handful of people who have found that “Unchecking Bi-Directional Support” on Port Tab’s, Printer Properties will magically cause printers to appear on their other iDevice. (PC only)
If none of the above resolve the issue, please proceed to Firewall and Router Troubleshooting.