Wi-Fi can't find networks after upgrade to iOS8
My stepson upgraded his iPhone 4S from iOS7 to iOS8. After the upgrade, the phone no longer finds any WiFi networks. Under "choose a network", there is a moving circle witch indicates an ongoing search, but the phone can't find anyting at all. It doesen't matter if we try our own network, or any others, the result is the same.
This is what I've tried so far:
1. Wifi off/on.
2. Tried to promt our own network using the "Other" under wifi. Typed in SSID and password manually, but finds nothing (there are no space in SSID-name or "hidden" network in our house).
4. Reboot (home + power-buttons).
5. Flight modus off/on.
6. Resetting the phones network settings.
7. Disable wifi networking services (Settings > Privacy > Location Services > System Services)
8. Tried to set custom DNS, but can't do (need an already installed wifi-connection to change this).
9. Reset/upgrade the phone using iTunes (no errors during upgrade).
10. Opened up the phone, and changed the wifi-antenna.
11. Put the phone in the fridge for 45 minutes.
But still no cigar... I'm out of ideas. What's next to do now...?
The option for downgrade to iOS7 is removed by Apple, and I don't wanna install any russian/chineese jailbreak-software on my computer either!
The phone is a few years, and has gotten the back cover (or is it called 'backshell' in english??) broken and changed twice (privatly done) - and now I've also changed the wifi-antenna myself, witch I suspect says goodbye to the Apple guarantee (the WiFi was OK after both back cover jobs).
Is this a good question?