Error when trying to check on AT&T subscription status

While of course it is possible that AT&T's servers were down at the time I think there is more to it than that. After I posted this note I subsequently noticed another oddity. And that is, when I tried to view my cellular phone number in the Settings menu, it said "Unknown". Very odd. So I still thing the problem is on the iPad side.

Can't try anything now, my wife made off with the iPad today. 🙂

I have an update on this problem just in case someone else runs across the same error, then they'll know what to do.

It isn't AT&T servers. I can reliably reproduce the problem at will.

When I turn off 3G, then turn off the iPad (turn off not just sleep) and then reboot the iPad, at that point the iPad can no longer see the SIM. I can't check my account using a Wi-Fi network, and also the iPad reports my cellular number is "Unknown".

However once I turn on the 3G network, all is good. Even if I turn 3G back off again, it knows my cell number and I can check my account via Wi-Fi only.

Until I power off the iPad again then the whole process repeats...

I spoke with an Apple Expert over the phone and then got an appointment at the Genius Bar at my local Apple store. He confirmed the problem, and that it should not be happening, and he swapped out the iPad under warranty. He put my old SIM card into the new iPad.

For a couple of hours it worked great, but unfortunately the problem came back. So it wasn't the iPad either as it turns out. That leaves just one thing: the SIM card.

So I guess my next stop will be at an AT&T store to swap out the SIM card.

I have another update. I waited until my data plan ran out and then visited an AT&T store to swap out the SIM card. Same problem. I didn't even leave the mall before I tested it and nothing changed.

Both Apple and AT&T thought something was wrong, and both agreed that their respective components should be replaced under warranty. However now that everything has been swapped out, I'm forced to conclude that this is simply the way that it works, despite the best advice and consultation from both Apple and AT&T. I'm guessing that something is being written to volatile memory when the SIM card is accessed for the first time that is being cleared when the iPad is being powered off. Until it is powered off, however, even Sleep mode retains the memory state. That's the only explanation that makes sense at this point.

Here's the test if someone wants to try it out on their own iPad:

1. Turn off the 3G antenna but be connected to a Wi-Fi network.
2. Check that the iPad knows the SIM information by either:
a) Settings->General->About and then you should be able to see your cellular number in that list, or
b) Settings->Cellular Data->View Account and you then should be able to sign on and check your AT&T 3G account even through a Wi-Fi only network

3. Now power off the iPad (not Sleep mode, a full power off).
4. Bring it back up and let it connect to the Wi-Fi network. The 3G should still be off of course.
5. Check that the iPad DOES NOT KNOW the SIM information by either:
a) Settings->General->About and then your cellular number should read as "Unknown"
b) Settings->Cellular Data->View Account and you then should NOT be able to check your account status. Instead you should get the error message "The device information was not received. Please close the page and reopen View Account (USIM9997)"

6. Turn 3G back on. Everything should go back to the way that it was originally.
Now, even if you turn off 3G, or even if you put the iPad into Sleep mode, it will remember the SIM information - until you power it off again, in which case the whole thing repeats.

Anyone care to run that experiment to test my hypothesis? If so, then when someone else stumbles across this problem in the future, we'll know the cause and Apple and AT&T can avoid replacing perfectly good equipment on a non-existent problem. Heck, they'll probably find the solution themselves just by Googling on "USIM9997" and running across this thread...

Thanks,
Ray