Nếu bạn update earlier to iOS 8.0.1. This update caused iPhone signal loss problems with cellular connectivity, Bluetooth, and WiFi
to fix signal loss. Connect your iphone to itune and update to ios 8.1.1 will fix problem.
1) Tap: Settings
2) Tap: General
3) Tap: About
4) Scroll down and look for 'Version'
|