iPhone 5 iOS 8.3 no wifi

Since updating to iOS 8 my iPhone 5 will not connect to wifi, neither at home nor at my parents, a message says incorrect password, but Androids, PC and Macbook connect without any problems using the same password.

I have tried everything I've read on the internet regarding this issue.

1. Restart telephone
2. Restart router
3. Reset network settings
4. Install iOS 8.3
5. Backup and reset to factory settings
6. Change SSID and password for WiFi
7. Reset SSID and password for Wifi to original settings
8. Changed SSID and manually entered a key

Once I changed the SSID and password (6) this also effed up all other iDevices that were previously working without a problem. Resetting the SSID and password didn't help with the other iDevices so I changed the SSID again and manually entered a key and finally the iPad and the iPhone 6's were able to once again connect to the wifi, The only unit that will NOT connect to wifi is my iPhone 5 which worked perfectly until it was updated to iOS 8.

Any suggestions on what else to try?

Thanks