My samsung galaxy j7 prime wifi doesn't working

@techside first you need to make sure that all of your settings are properly set. You could also consider a factory reset. Do that only after you back everything on your phone up. Make sure that you have the proper email address and password that was used when this phone was set up.

Lastly, you may need to consider checking the hardware according to the Samsung Flowsheet

Next, use the search function on your PDF reader to find the components to measure, on your board (i.e. C1103)