Wifi issue since day 1 got the phone. I can connect to my router n browse the net for bout 1-2 minutes then no connection despite full bar of wifi strength on notification bar. Need to pull down menu, turn off n on again wifi to be able to surf again. That also last for 1-2 minutes before same thing happen again.

What I've tried:
- forget network n enter settings again
- hard reset phone
- take out sim card
- reset my router
 
Any help is greatly appreciated. Now really no time to go to service centre esp if have to leave it for few hrs or days to repair..