[ksyen]

my phone doesn't have connections to my at&t Sim card .. when i try to put check on the mobile network, even though it has check mark already there's still a red x mark on the left side.. (mobile network) but when i try to use my other sim card (its a ROAMING SIM CARD) from the philippines, it's working. the set up is in GSM and in 2g and my phone is unlocked. i dont know why its not working on my at&t Sim card. help pls. thanks!!

[Greenhawk]

Try cleaning the gold part of the sim card?

[drphil1]

Check service book and make sure you have the right APN settings.

[ksyen]

what's apn?? what should be the right apn?