I'm a newbie in this forum.I'm using W810i and all of a sudden my mobile turned off and I'm not able to turn it ON.When I try to turn it ON,it just flashes a white screen for a sec and goes of again.

Can some one please help me sole this problem and help me turn it ON.

I even dont know how to check the existing firmware and dont know which firmware files to download to restore my phone.

It would be very kind if some one please post step by step instructions on how to solve my problem.