Before you send back your old phone test the replacement one thoroughly.
They tell you to return the defective one within 48 hours, but the fact of
the matter is they actually give you 30 days. I know, I used to work there.

If after testing the replacement phone you still feel it's the SIM, go back
to the store and have them replace the card again. If you find your old
phone was in fact NOT defective you can return the replacement one instead
and they should refund your $14.99

As far as the "SIM CARD REGISTRATION FAILED" error goes, it's actually
fairly common within AT&T. It's been attributed to a variety of things.
Usually it ends up being a software issue on phones. On one occasion it was
discovered that the SIM cards from a certain vendor were more likely to
cause this error in a certain LG phone. One would think that all SIM cards
were created equal, but not according to this temperamental LG phone.


"MAG" <[email protected]> wrote in message
news:[email protected]
> Hi folks-
> My 6820 has occasionally given me "SIM Card Registration Failed" errors
> since I bought it a month and a half ago. It always before went away
> with a reboot.
> Today I took it in to the ATT store and showed the folks there. They
> suggested it was a flakey SIM card and gave me a new one, registering
> the new one first.
> We swapped the new one into the phone and booted up. Got the same error
> about failed registration.
> They said the phone itself was at fault, and made me call the warranty
> replacement number. It's costing me $14.99 to get a replacement shipped
> to me; should be here tomorrow or next day latest.
> I guess I'm worried because when the new phone gets here, I'm worried
> that I will put in the SIM card and get the same error; another way to
> say this is that I'm afraid they screwed something up when registering
> the new SIM card.
> An interesting note is that I can save contact names to the new SIM
> card, so I know that it is communicating with the phone. I didn't try
> this with the old SIM card.
> My running theory has been an intermittent fault between the phone and
> original SIM card, and now I'm worried that the replacement SIM card is
> wonky.
> Any thoughts here? How common is this error? Anybody have any similar
> experiences?
> Marc

See More: "SIM Card Registration Failed" with AT&T Wireless