nokia lumia 900

[mrpapid22]

i have at&t nokia lumia 900, i try to unlock it, but at the end it display "sim card is missing or invalid.", then "no service-emergency call only." the sim card is new with a current phone number. Pls i need help with this phone.::unhappy:

 

[MDK22]

Soooo, did you unlock the phone ?
It'll display a graphic w an unlocked padlock. dial ##7820# to check (works on my Lumia 1520 - ##782# for other devices) ...

and, what carrier's sim card are you using ?