Hi All, I have an interesting iPhone 4S on my hands to see if anyone can help me. It is an iPhone 4S model number: MD277LL/A which indicates its a Verizon. I purchased it, but it apparently still has the CDMA settings flashed. So my Carrier displays as vf nl 16.0. I understand the 4s is a world phone. So unlocked I figured I would be good, right? However, using China Unicom cards, I have no service, and occasionally I get the Carrier name with 0/5 Bars of service. I cannot make or receive calls or texts on this card. The SIM is verified working. China Unicom uses the GSM 900 / GSM 1800 / UMTS 2100 frequency bands for its network. I know with my iPhone 4, I can connect to 3G network automatically. So I switched to a China Mobile SIM, with this I get full signal, can make and recieve calls. And after switching data roaming on, I get edge, which is correct because they use a propitiatory 3G tech. However iMessage and Facetime will not activate and I cannot 'read' the sims number. So I know this phone is not locked. But it autofills in the APN settings with some vodafone account. And I cannot get it to work. I am stumped!!