Printing wireless

If you previously had this printer connected to the Mac via USB cable and then disconnected the USB cable and connected it to the Airport router, then you will have to add the printer again. Because the printer currently in Print & Scan on the Mac is for the USB connection and will not print to the networked printer.

So, open Print & Scan and select to add by clicking the plus button. With the Default view selected, the printer should appear in this view. If it does, select it. The Print Using menu should automatically select the appropriate printer driver and you can click Add to complete the print queue creation.

Now you should be ready to print.

The Airport Extreme uses the Bonjour protocol to advertise the printer connected to its USB port. If you cannot see this printer then you could have an issue with the Bonjour protocol. To check this, you can use Safair, but you need to enable the Bonjour bookmark via Preferences > Bookmarks, as shown below.

With this enabled you will now have a Bonjour entry and when selected, if the printer can be seen by the Mac it will be listed.

So can you see your printer using this method?

If you open Airport Utility and click on the Extreme base station, does it show the printer connected via USB?

Also, have you tried turning off the power to the printer for a few minutes and then back on again?

Maybe this issue with the utility being unable to connect to the Extreme is tied in with the printer not appearing in the Add printer window or Safari > Bonjour. Even though your Internet is still working, I would be turning off the Airport Extreme for a couple of minutes and then turning back on. But, I would only do this if you have another option to gain Internet access. Because if there is something wrong with the Extreme, then turning it off and then back on could stop your Internet access.

Can you connect to the Extreme with Airport Utility?

Like you tried before. Open Airport Utility and see if it connects to the Airport Extreme.

Previously you said "I open Airport Utility I get an empty gray box with one of those continuing circles indicating that it is working on something and a message saying that: "No configured Airport base stations have been found."

So I was wondering if this is still the case or has this been fixed since you turned the powered off the Extreme and turned it back on.

The Airport Extreme is a base station so it is unusual that the utility cannot find it. I do believe that this is related to the Mac's inability to see the printer when it is connected to the Extreme.

Could you open Activity Monitor (Applications > Utilities) and in the top-right corner of the application, if it says "My Processes", change it to "All Processes". Then look through the list of processes for mDNSResponder. If you don't see it then you could try to manually start it by opening Terminal and typing the following command:

sudo launchctl load /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Then switch back to Activity Monitor and see if the process is running now. If not, the service is having trouble launching and this is stopping the Mac from seeing the printer (and impacting Airport Utility).

You could then check the Console application (also in your Utilities folder) and see if there is any mention of Bonjour (Multicast DNS) crashing.

If you see mDNSResponder in the list then there is nothing that you need to do. This indicates that the process is running on your Mac so it should help with discovering the shared printer.

Not sure what else to suggest you try at this stage. Need to have a think about your symptom and get back to you.