"No Service" after 4.2.1 update on Iphone4

[grand_archon]

Hi guys.I updated my recently bought I4 last night to iOS 4.2.1. I bought this from UK. The phone with the sim I was using was operating perfectly. After updating, the signal was gone and "No service" is shown on the phone. itunes indicates "the sim card inserted in this phone does not appear to be supported". i inserted the same sim card on my sony ericssson phone and it is functioning fine. Why does my I4 indicate "no service"? What should I do? Thanks

 

[DannyBoy]

Sounds like you have a phone that is locked to ATT. If so you will need it jailbroken and unlocked for it to work. That being said the only jailbreak is tethered and there isnt an unlock out yet... So sounds like you may be waiting for a bit until it's released.

 

[iGaz]

Double thread