Iphone 3G greyed out wifi button

Recently i found an iphone 3G in my grandparents room that is in pretty good condition. I decided to mess around with it for good times sake,

but it said there was no wifi. i then went to the settings to put it on our wifi network but the button was greyed out and said "No Wifi" here are some things i have already tried

-putting it in the fridge

-restarting it

-reseting the settings

-reseting it to factory

-reseting network settings.

please help me out that would be nice