iPhone 4S, INVALID SIM or NO SIM message ...

[cmeisenzahl]

I got this last night and tried a couple restarts with no luck. So I called Apple.

This worked the first time, and so far, still okay.

1. Enable Airplane mode
2. Reboot phone
3. Disable Airplane mode

Apple also said that resetting network settings often works, too. Just passing this along in case it helps someone else.

 

[edk99]

This sounds like the same issue I was having and may other people were having with the iPhone4. Flipping airplane mode on and off worked. Also try taking the SIM out and put it back in. If it keeps happening just take it to Apple and get it replaced.

 

[Mr.C]

I had the same problem with my iPhone 4. I use to restart it in the beginning. In the end I ended up getting it replaced.

 

[cmeisenzahl]

This sounds like the same issue I was having and may other people were having with the iPhone4. Flipping airplane mode on and off worked. Also try taking the SIM out and put it back in. If it keeps happening just take it to Apple and get it replaced.

Thanks, that's what I figured. If it happens again I'm off to the Apple store. ;-)

 

[kozz]

I had this happen to mine after visiting a apple store to get a replacment, verizon thought it was a bad sim and replaced it with a 4g sim (im awaing a new 3g one). Long story short the apple store inputted that I have a sprint phone and thats why i could not activate it on verizon, and that night after restoring it from itunes it turned my phone into a sprint one. It took me 1.2 a day to get ahold of a senior tech support agent who had a clue, and that night I was able to restore it and get back on verizons network. I will have my new sim today so I have to test the activation part again.