iPhone 4 “No Service”

So I turned on my iPhone 4 the other day to be greeted with “No Service”. I have had repeated problems with Unrecognised SIM which I fix by turning the phone’s Airport Mode on and off which temporarily fixes it (according to Apple the phone is working perfectly!)

However this wasn’t fixed by a simple toggle. I went through a whole load of things, from swapping SIMs with a friend which still showed No Service, although the SIM worked in their phone to phoning O2 and asking them if they had cut me off.

However eventually I found a fix:

• Go to Settings
• General
• Reset
• Reset Network Settings

This causes the phone to reboot, once it had all come back up I got O2-UK appear again. The only thing is remember to find a record of your Wi-Fi passwords as this will wipe them and you will have to enter again.