Laptop does not turn on. What to do?

I have a lenovo G560 laptop with windows 7 ultimate. When I turn it on, there's firstly a white flash and then it is blank.
I have tried to remove the battery, press f8 and start it in safe mode, but it turns off after that. What can be the problem and what should I do? Is there a possibility that the operating system had crashed and if yes, how can it be resolved.