flashing screen

Hi can anyone out there help, a 6 month old macbook won't respond to anything, (well maybe a 2lb hammer) when the on button is pressed the screen just flashes, and nothing else happens, Battery in or out no change,
no beeps no clues,
Have read quite a few threads but nothing is similar ...
So any suggestions before the hammer would be very welcome.

Maybe your hard drive failed? Take it to an apple retailer store and have them look at it..

Thanks for that, will do.