I'm failing to activate my iphone 2.1

Question

Hi guys I upgraded my iphone from firmware 4.3.5 to 6.1.6 but then it's failing to read a simcard. As a result, I'm failing to activate it without sim
anyone with an idea, pliz help

Answer 1

The second generation iPhone does not support iOs 6.1.6 so this may indicate either you do not have an iPhone 2 but rather an iPhone 3GS.  If you have an iPhone 3GS.  You probably need to jailbreak it in order to accept a foreign sim, could be that your iPhone shipped locked, was jailbroken and after the upgrade you lost the jailbreak!

read the following for information
http://www.iphonehacks.com/2014/03/jailbreak-ios-6-1-6-redsn0w-p0sixspwn.html