Hi. I'm one of the iPhone 4s user. I also bought iPhone 4s for my wife. Three month back, I update my wife's iPhone from IOS 5.0.1 to IOS 6. After that, I update mine to IOS 6. For my wife iPhone, after a month using the new IOS, the wifi suddenly her iPhone cannot detect any wifi connection. Then, she ask me to fix it. I decided to restart her iPhone. I thought, after restart,the wifi will be working again. Unfortunately, the wifi button become grayed out. I cannot even turn it on. Then I decide to send it to the dealer since her iPhone still under warranty. Then send it back to Apple and Apple change it to a new one.
For my iPhone, everything is fine and I update to IOS 6.0.1. The latest version. Last two night, suddenly my iPhone cannot detect wifi. And then, I turn the wifi button off and turn it on again. The result is still the same. Then I decided to downgrade the IOS 6.0.1 to IOS 5.1.1. Last night, I try to downgrade using Redsnow. Unfortunately, I failed to downgrade the IOS and the best part is, the wifi is back to normal. I can turn it on and off and also connect back to my home wifi.
How I do it? Just follow below step. Please note that, if you turn off your iPhone, the wifi will become grayed out again.
File needed :
Redsn0w 0.9.14b2, IOS 5.1.1 firmware.
Step 1 - Download two file from above link.
Step 2 - Double click the Redsnow 0.9.14b2
Step 3 - Click on Extras
Step 4 - Click on Even More
Step 5 - Click on Restore
Step 6 - Click on IPSW and locate the IOS 5.1.1 firmware that you just download.
Step 7 - Click Ok on the warning.
Step 8 - Connect you IPhone
Step 9 - Click Next
Step 10 - Let the application finish checking
Step 11 - After about one hour, the application will tell you that downgrade is failed.
Step 12 - Just disconnect your iPhone and restart it.
Step 13 - Check on the wifi setting. It should be ok already.
Good luck...
Note: Try at your own risk. I had tried it and success.
Reference :
http://www.redmondpie.com
