Dell precision M4700: Wireless failed after ubuntu 12.04 updating

[rbaena]

Hello everybody,

hope somebody can help.
I am working on a Dell precision M4700 laptop with Ubuntu 12.04 and KDE desktop.
After a "suggested" system updating, my wireless connection stops working. KNetWorkManager sees the wireless and tries to connect to it but, after a while, a small windows pops up and asks for a password. If I introduce the wireless one I have it tries again but nothing happens. That window appears again and again asking for a password.
Such windows has a key as a symbol on the top left corner, the same key appears over the KNetWorkManager symbol which is on the bottom panel. The window has the title "Secretas de [wireless name] - Service for KDE-" (in Spanish sorry ).

I guess some security measurement has been activated after the updating but I do not know how to deactivate it.

I am sure the password is correct and the router is working fine, indeed, I am using another laptop to publish this thread using the same wireless connection.

I also post some useful information:

kernel: 3.2.0-37-generic
desktop KDE
ubuntu 12.04.2 LTS

iwconfig:

lo: no wireless extension
eth1: IEEE 802.11abg ESSID off/any
Mode: managed access point: not-associated
Retry long limit:7 RTS thr off Fragment thr off
power management: off
eth0: no wireless extension

Thanks for your support!

[chili555]

Please see your question at askubuntu.com.

[Merrattic]

Which is here: http://askubuntu.com/questions/25637...12-04-updating

Try turning the hardware wireless switch off if you have one? On my Dell Precision M6500 I have to have it on for W7 but off for Xubuntu 12.04.2.

[rbaena]

Thanks for your answer.
I do not see any hardware switch to set off the wireless device. Where is it?

[chili555]

Please see #13 attached.

[rbaena]

Thanks, I tried switching off the button #13 but it does not work either.

[marioman619]

Hi, I had the same issue before but once I installed the latest version the problem seemed to have gone away. Otherwise I think you can fix it by downgrading the kernel to the one with an Ubuntu version that worked.