Ipad2 update IOS5 to IOS 6.0.1 stopped seeing sim card?

Question

iOS

After the update, I stopped seeing the SIM card.
With IOS5, it worked fine with the SIM card.
ipad from the USA or from Singapore, I don't know for sure.
What should I do?

Answer 1

1) the first thing that comes to mind is to check the sim card.
My sim card just died for 2g once after the firmware.
2) there was a universal modem on the ipad so that it could not be blocked or something else like that
3) what kind of ipad do you have? windows? macos? I will try to advise as much as possible.
4) completely flash again into a clean one.

Answer 2

+ The SIM card could die purely by accident: I just stopped seeing the SIM card literally two or three months after the purchase. So far, I haven’t taken it to the service (GPS works, and okay).