Cannot connect to wifi

my phone's wifi is not working

my wifi signal strength is very strong but it's not able to connect

the status shows obtaining IP address

and after a while it tells network disabled. Poor connection

I checked on the net they say it's because of the update of the phone original version 4.1.1 to 4.1.2 jelly bean, the update is causing the phone wifi connection go crazy

I checked for the solution, in many forums they showed to change the IP settings from DHCP to Static which I did and then after entering the wifi password there is no save option

I tried this way too..the link is below

https://www.youtube.com/watch?v=zyO66lqT...

the first way is dialing *#0011# but it's still not connecting

the second way was too confusing so I didn't try

I checked it online and I guess this problem does not only happen in note 2 but almost all the android phones