ok after installing the broadcom-STA-wifi-driver the problem is completly gone. so finaly it turn out to be a driver issue.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1256949 Title: Dell Latitude E5420 doesn't boot if killswitch is turned to "radio off" Status in “linux” package in Ubuntu: Incomplete Status in “upstart” package in Ubuntu: Incomplete Bug description: Ubuntu 12.04.3, Dell E5420. Boots fine with killswitch to "radio on". To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1256949/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
