hi my acer 5520 will power up but wont boot. alls i get is a black screen and the power light will flash on and off. the cd drive also clicks but if i open it it stops. the screen doesnt display anything, and the fan kicks in for a few seconds then stops. I can press fn and esc and power and the power light will flash orange and then the laptop power light will stay on constant but the screen still displays black but the fan will stay on full when this is donre