It's possible that your device has got some hardware issues.
1.This is a step that works especially if you are facing any issue with an individual WiFi network. If your Samsung Galaxy A02s is not connecting to WiFi which is from a single router but works fine on others, the best thing to do is to forget the network and reconnect it.
Whenever you connect a device all the details of the network will be saved. So, any kind of change in settings may stop you from connecting to that specific network. In this case, go to the Wifi settings menu and find the network you are having an issue with. You can find the forget network option by either tapping and holding on to the network name, or by clicking on the ‘i’ icon next to it. Once you forget the network, start fresh, and reconnect it by entering the password.
2.If you are still not clear of why your phone won’t connect to WiFi, there might be some hardware issues on the device. If the WiFi receiver on your Samsung Galaxy A02s stops working then you will not get any kind of signals and won’t be able to connect to a network. In this case, always get official technical help.
Always avoid doing such repairs by yourself as it can break the device. Any kind of unofficial technical help is also must be avoided. Make sure you contact an officially licensed service center to make hardware changes to your device.
