Hai guys I have some problem with my iphone, the screen went black all of a sudden when I use facetime, but it still can hear and receive calls (though I cant pick it up even though I slide it)

What do guys think the problem is? Is it the lcd? or the sensor?

Btw, I bought this phone at the US, and I think I should claim the warranty there?

havent jailbreak my phone, I'll try send it out to our local phone service

You can just google it. Here what I find:

Follow these steps to set up contact syncing with Google Contacts:

Tap Settings > Mail, Contacts, Calendars > Add Account > Other > Add CardDav Account.
Enter the following information in the fields:
Server: google.com
User Name: Enter your full Google email address
Password: Your Google account password
Select Next at the top of the screen to complete the setup.
After you have completed the setup, open the Contacts app on your device. Syncing should begin automatically.

Additional Information
Note: Make sure that SSL is enabled (under Advanced settings), and that the port is 443.

Nowadays, 16gb seems not enough as I keep on recovering back from previous generations

If my iCloud is full, can it still recover back the data?