[iMore Question]

iphone 4S wifi button greyed out after installed update

[iOS Gravity]

Try reseting the network settings. You will need to restore if reseting the network settings doesn't work.

[bianca47orchard]

Hard restart (hold the home button and sleep button) can usually sort this out. If you still have trouble, reset your network settings or fully restore the phone, as mentioned above.

This WiFi issue is pretty common with 4S that were made for a few specific carriers. At some point, the WiFi greys out permanently because your chip has come loose, so the only fix is a refloat your WiFi chip. It's not an expensive repair, just make sure the shop has a good policy around this type of repair (e.g. refund if unsuccessful, 4 refloats after your initial payment if the fix doesn't hold, etc) because it's a tricky thing to make stick.

[cisneroscad]

iphone 4S wifi button greyed out after installed update

Did you get it fixed? I have an iPhone 6 with the same issue

[jrocke0w0]

Did you get it fixed? I have an iPhone 6 with the same issue

I just fixed my mother-in-laws 4s by what I thought was a ridiculous fix.
-heat the phone up with a hairdryer until the temperature warning comes up on your screen and then shut the phone off. Next put the phone in a ziplock bag (sealed) and put it in the fridge to cool back down for about 15 minutes. Now turn it back on and your wifi should work. I found it on YouTube and thought it was crazy but had nothing to lose so I did it and it works. Unbelievable I know.