SIM Card Rejected :
SIM card rejected error messages may be the result of four causes.
* The first possibility is that the card is misaligned, which may have been caused by bumping, dropping or opening the phone.
* Another possibility is that the Personal Unblocking Key (PUK) code may have been entered incorrectly and repeatedly, resulting in inactivation which could be permanent.
* A third possibility involves a recent change in service providers, necessitating a reconfiguration to appease the standards of the new service provider.
* The fourth and final possibility is that your SIM card could be damaged and require replacement.
Codes Requested :
Your SIM card is protected by the PIN code, which is set by you, and the PUK code, which is set by your service provider. Incorrectly entering your PIN multiple times may result in a prompt asking for the PUK code, and if the PUK code fails to work, you may need a new SIM card.
Swapping SIM Cards :
Although the physical action of transferring a SIM card from one phone to another is simple enough, the practical reality of the matter is that most providers lock the phones they provide, meaning, for the common customer, that phones can only be used solely on the networks for which they were originally purchased.
Minute Drains :
Another problem that users have had trouble with involves a loss of minutes after switching to a new SIM card. Because of this, you should speak with someone at your service provider prior to accepting a new SIM card, in order to ensure that your minutes are retained.
Bad Batches :
There have also been instances where substantial numbers of bad SIM cards were released. This seems to have occurred after the release of the iPhone in 2007, when many users found their excitement for the new product stymied when they faced messages such as "invalid SIM" or "No SIM card installed."
Virus Infection :