[aprilxia]

I have a BB8120 with AT&T, but after I put in AT&T SIM card, I can't make call or other operations, I can see "SOS" besides the signal sign.

Do i need to activate SIM card first? How?

Thanks

[NJBlackBerry]

Was the card used in another phone?

[Marruenda]

this might sound stupid but have you tried turning of the radio completely (AKA airplane mode w.e u wanna call it) and then turning it back on again. this happened to me once and i did that and it worked.

If not like NJblackberry said. was the card on any other phone? if so just call up att from another phone they'll activate it for you