HP touchsmart ENVY 23 black screen problem

I have HP ENVY Recline Touchsmart All-in-one PC ,, Model No, 23-k000ee .. with windows 8.1 enterprise installed . It was working fine since 8 months with no problems . Yesterday . I have finished my work & close this PC normally as usual , but today when I turn it ON , Ive got only a black screen , even cant see the HP logo at startup , just when turn it ON, the screen lights for about 2 seconds and then goes black and still black and cannot see any thing . Any one can urgently help me because I need to use it ASAP to finish my work ,