My American version of iphone4s has a lock. With the card, I can make phone calls and receive text messages, but I can't send text messages and surf the Internet. There is no APN option in China.

Hello, according to your description, it is possible that your online parameters are wrong, which makes it impossible to use. The specific settings are as follows:

The network setting method of iPhone is as follows:

1. Settings-Flight Mode-Off;

2. Settings -wifi- can be turned on or off;

3. Settings -VPN- Off;

4. After setting-operator-search, you can find CHN-CUGSM; Rely on yourself;

5. Set-Push-Open, access can be selected at will, usually manually;

6. Settings-General-Network-Enable 3G- On.