Our family has just bought another iPad 2 - this one off a close friend. Said friend has never inserted a Sim card to the iPad, and bought it from the Apple store in Birmingham, UK. Please note; I personally bought an iPad 2 3G two weeks ago which is working perfectly with 2 sim cards (mentioned below). When a Sim card is inserted (the O2 one from my iPad, or an unused '3' Sim), the iPad immediately pops up with 'Sim card failure' and displays 'Invalid Sim' as the carrier. I've tried the following: Restore to iOS 5, clean Re-inserting the Sims multiple times Resetting/rebooting several times The iPad activates fine, but seemingly not via a cellular network. Eventually it just displays 'No service'. This is rather frustrating for both us and the seller as we want the discounted iPad, and they want the money. The iPad was only bought in April so is it still in guarantee?? Anyone else with this problem managed to solve it? Is it a definite hardware issue? Suggestions/tips more than welcome. Are these two Sim cards I'm trying to use locked to my iPad only? ie. Will not work on the new family iPad?