Ubuntu – Suddenly stopped showing the wifi in ubuntu 14.04 in the list in Dell Inspiron 5420

14.04inspironwireless

Suddenly stopped showing my wifi in ubuntu 14.04 in the list in Dell Inspiron 5420,googled a lot,could not go through a working solution.Any Ubuntu user faced the same,please help me?
https://askubuntu.com/…/only-my-wifi-is-not-working… This thread have the similar problem but it is not working.
Earlier It was working as perfect,don't know what happened!