Hi, I am very new to the Android world. Got a SGH-i777 from AT&T in US in February 2012 and had to move back to India in June. I got the unlock code from AT&T and used the device for 2 months without issues here on the local network. Yesterday, the phone showed me a critically low battery message all of a sudden (I had fully charged it the night before) and turned off. When connected to the charger, I get the image of the battery with a yellow triangle with an exclamation mark in it. Thinking it may be a battery issue, I took it to a local Samsung repair center and he tried using a working battery in it, but still got the same image. He suggested that it may be a motherboard isssue. Please help !!! I am still in the AT&T contract. Any chance they will honor a replacement at this point? I tried a long continuous charge and got a battery 100% charge indication, but when I try to power up the phone the same thing happens and the phone doesnt power on.