Xperia T won't turn on after charging

[Robbie97]

Hi, i have had my xperia T for about a year and a half now and this is the only real problem that's popped up. I put my phone on charge over night (as i normally do) and this morning it wouldn't start. There is a little green dot in the top right corner please help!

[_alexdon_]

Force restart (power button+volume up at the same time until the phone vibrates).