How to Fix iPhone 4s Wifi Issues or Grayed Out or Dim
* Make sure that wifi issue on your iPhone 4s is occurred in all wifi hotspot you met.
* If this wifi issue only occurred in one wifi hotspot such as your home or office, while in the other wifi hotspots you did not find any issue, contact the wifi provider or IT support whose responsible there.
* Wifi issue have you met still occurred even though the third party case which is stick on your iPhone 4s has been taken off.
Of course you can do all the steps below or maybe one of those steps is fit for you and your iPhone 4s wifi issue solved
* Restart your iPhone by pressing and holding the power and home button until it restart.
* Power off iPhone by pressing the power button for some times until “Slide Power Off” appears, then slide it to the right. Then Switch it on by pressing power button for seconds.
* Go to Settings >> Airplane Mode (swipe it On and wait around 15 seconds the turn it on again).
* Disable Wifi Network Service. This service is connected with Location Service Network. Go to: Settings >> Privacy >> Location Service >> System Service (swipe it off).
* If your iPhone can connect to wifi but cannot be connected to the internet, try to do “Forget Network”. Go to Settings >> Wifi, tap i sign next to the wifi host name then tap Forget this Network.
* If internet connection is still not working, change DNS on that wifi host name. Go to Settings >> Wifi , tapi sign next to the wifi host name then scroll until you find DNS, tap it. Change the most used DNS like DNS from google 18.104.22.168 or another openDNS.
* Reset iPhone Network Settings. Settings >> General >> Reset >> Reset all Network Settings. iPhone will restart to do this Reset Network.
* Erase all content and settings. Settings >> General >> Reset >> Reset all content and settings.
* Restore iPhone. Plug iPhone to Mac/PC then launch iTunes. Tap Trust on your iPhone popup message. your iPhone will be detected in the iTunes and on tab summary click Restore. Firmware will be download first and wait for the process to be done.
* Restore iPhone in recovery mode. To take your iPhone to recovery mode: Plug iPhone to Mac/PC then launch iTunes. Hold down power button and home button until the iPhone restarts and when Apple logo starts to appear, release the power button but keep on pressing the home button until iTunes sign and cable lightning on your iPhone 4s screen are appear. Choose Restore and iTunes will download firmware that is need and restore your iPhone 4s to factory setting.
* Restore your iPhone 4s in DFU mode: plug iPhone to Mac/PC then launch iTunes. Hold down power button and home button until iPhone restarts. Count until 5 seconds and release power button but keep pressing the home button. If it succeeds, your iPhone screen will remain dark but iTunes will detect your iPhone 4s in recovery mode. Choose Restore and iTunes will download firmware that is need and restore your iPhone 4s to factory setting.