Can't connect wirelessly HP Photosmart C4780 to MacBook Pro OSX 10.8.2 Mountain Lion.

Question

Hi!
Didn't know exactly where to direct this question in the Apple Community so I chose Airport.  To everyone, thanks in advance.
I’m really desperate. I’m a big Apple fan.  I have two Apple MacBook Pro laptops with Mountain Lion software.  I also have an Apple Airport Extreme.  My HP Photosmart C4780 printer was also purchased from Apple.  Anyway, my Internet service is AT&T.  AT&T just upgraded my service with a new modem/router (AT&T U-Verse).  Prior to the conversion, my wireless printer connection was working perfectly.
Now can’t print wirelessly. For your information, everything is connected via Wi-Fi. The AT&T technician stated that I no longer needed my Apple Airport Extreme, so it was removed.  Naturally, after the tech leaves, we find out the HP printer wirelessly no longer works.  Thinking that removing Airport Extreme may have been the problem, I reconnected it to the AT&T modem/router, however no change.
This appears to be an HP printer problem.  I went to HP community support with the information below but I have received no solutions outside of buying a new printer.
“Ran the HP wireless network test report and it states that HP printer can’t find wireless router and to verify that the HP printer network name (SSID) matches the wireless router network name (SSID) exactly.  The Diagnostic Summary in brief:  Wireless On & Working & Security – Pass; Network Name (SSID) Found – Fail. Nothing else under diagnostic summary ran.  Under Configuration Summary:  It shows old SSID name and Mac Hardware Address but no IP Address.
Next ran the Network Configuration Page and everything is enabled except the 802.11 Wireless.  It shows status – disconnected.  Under general information it states the following: Network status  - Offline; Active Connection Type - None; URL(s) for Embedded Web Server – http://0.0.0.0.”
To be straightforward, I’m no computer tech so I don’t know what this means or where to find.  The AT&T tech provided me the new SSID Name and a wireless key number but that’s it. Also I uninstalled and reinstalled via USB. The HP message states can’t find router. At this point, I’ve tried everything to reconfigure without success. If I need to make these changes via Airport Extreme Utility 6.0 not easy to find not that I know what I’m doing.
Most importantly if I ever get wireless working again, do I still need Airport Extreme connection or is the AT&T U-Verse modem/router sufficient?
Any direction or help is greatly appreciated.  Thank you for listening.

Answer 1

Thank you for your prompt response.  I'll be honest I'm a retiree and a newbie to all of this stuff. I don't even know how to do a thread. (Embarassing) This is my first ever contact with the Apple Community so I'm slowly trying to figure this out as well. 
As to your thread request, I'm assuming you want to read my post with HP.  Not knowing how to thread, I've copied it below.
I have an Apple MacBook Pro laptop with Mountain Lion software.  I also have an Apple Airport Extreme.  My Internet service is AT&T.  AT&T just upgraded my service with a new modem/router (AT&T U-Verse).  Prior to the conversion, my wireless printer connection was working perfectly.
Now can’t print wirelessly.  For your information, everything is connected via Wi-Fi. The AT&T technician stated that I no longer needed my Apple Airport Extreme, so it was removed.  Naturally, after the tech leaves, we find out the HP printer wirelessly no longer works.  Thinking that removing Airport Extreme may have been the problem, I reconnected it to the AT&T modem/router, however no change.
Ran the HP wireless network test report and it states that HP printer can’t find wireless router and to verify that the HP printer network name (SSID) matches the wireless router network name (SSID) exactly.  The Diagnostic Summary in brief:  Wireless On & Working & Security – Pass; Network Name (SSID) Found – Fail.  Nothing else under diagnostic summary ran.  Under Configuration Summary:  It shows old SSID name and Mac Hardware Address but no IP Address.
Next ran the Network Configuration Page and everything is enabled except the 802.11 Wireless.  It shows status – disconnected.  Under general information it states the following: Network status  - Offline; Active Connection Type - None; URL(s) for Embedded Web Server – http://0.0.0.0
To be honest, don’t know what this means or where to find.  The AT&T tech provided me the new SSID Name and a wireless key number but that’s it. Also I uninstalled and reinstalled via USB. The HP message states can’t find router. At this point, I’ve read your forum and tried everything to reconfigure without success. Any direction or help is greatly appreciated.
Thanks in advance!
Re: Can't connect wirelessly HP Photosmart C4780 to MacBook Pro OSX  10.8.2 Mountain Lion.              
I finally figured it out! (Sorry that I'm replying to my own posts btw, but I want to post the solution for anybody else with the SigmaplusEOL1 problem). If you have the SigmaplusEOL1 as your SSID when you  print the "Wireless Network Test Report", you do NOT need to return it (I know that's hassle for people).  To fix the problem, follow these steps.
1) Unplug your printer.
2) Go to your router's IP address (like 192.168.1.1 or whatever it is for your router).
3) Change the SSID of your wirelss network to "SigmaplusEOL1".
4) For the Security option for your wireless network select none (so that a password is not required to access your wireless network).
5) Power your printer back on and reprint "Wireless Network Test Repor". It should say "No problem found..."
6) The report should also have a the IP Address of the printer (under Configuration Summary at the bottom). Type that IP Address in your browser to get to the printer's settings page.
7) Click the "Network" Tab at the top.
8) Under the "Connections" header in the left pane, click "Wireless (802.11).
9) Click "Start Wizard" at the bottom right.
10) In the wizard, change the SSID and encryption (wep or wpsk) password to whatever you want your wireless network to be. So probably whatever it started out as before you changed the SSID to SigmaplusEOL1
11) Click "Finish" at the end. The page will probably try to keep loading but it won't because you changed the network settings of the printer. Just ignore that
12) Go back to your router's IP address and change the SSID and encryption password to whatever you changed the printer's SSID and password to.
13). Reprint the Wireless Network Test Report. It should say the SSID is the same as your wireless, and everything is good.
That's it. You should be good to go now.
Re: Can't connect wirelessly HP Photosmart C4780 to MacBook Pro OSX  10.8.2 Mountain Lion.              
Thank you for your prompt response.  This has been a totally frustrating experience.  I’ve spent at least 8 hours trying to fix this.  My HP problems and your initial steps were identical to mine.  I am by no means a tech person and my computer tech knowledge is minimal.  However I followed your steps to the best of my ability.
I did get the SigmaplusEOL1 message.  I was able to get to Step 6 where the wireless network test report now reads – “HP printer settings do not match your wireless router settings.”  So I guess this is a step in the right direction.  However unfortunately the Configuration summary message for the IP Address reads – “Not Applicable”.  (Note: changing SigmaplusEOL1 to network name knocked out my Internet access.  Had to switch back to regular network name to regain access.)
I’m at a loss as to what to do next.   Without the IP Address is it possible to move forward?  As I stated earlier, I’m not a tech person.  As to your steps 7, 8 and 9, I can’t find them on my computer or maybe I’m looking in the wrong places.  In System Preferences - Network, I have none of these steps.  If you’re referring to Airport Utility, with the changes in Mountain Lion, these steps are no longer there. If you’re talking about Safari, Firefox or HP, now I’m really lost.
Finally, I don’t know if you can answer this or not.  If I ever get wireless working, do I still need Airport Extreme or is the AT&T U-Verse modem/router sufficient?
Again thank you for your time and patience.
Re: Can't connect wirelessly HP Photosmart C4780 to MacBook Pro OSX  10.8.2 Mountain Lion.                  
Unfortunately I am unable to offer any further advice as I only followed the instructions listed on the other page.
Finally, as to having WEP enabled, I don't know.  Don't even know where to look.  The best that I could determine is that my security is WPA/WPA2 Personal.
I'm truly sorry about all of this.  Thank you for your time and patience.  After reading all of this and you change your mind, I would understand.