I'm looking to upgrade from an iPhone 4 to a 4S and want to buy a used one on eBay. I'm seeing a lot of them sold as 'faulty' going for a lot cheaper. Obviously if it's something that I can easily fix by restoring or similar then I'd go for a bargain, but I doubt many of the 'faults' are that simple to fix otherwise their owners would have solved the problems before selling......right?? So what are some easily identifiable issues that are relatively simple to solve? For the record I'm seeing issues like: SIM card not recognised 'No Carrier' displayed Phone stuck on Apple logo Phone stuck on activation screen Are any of these easily fixable?