I have a Toshiba satellite C655-S5512 with windows 7. When I push the power button to turn it on the light indicator in the front is green and the number lock indicator turns green but the screen stays a blank backlighted grayish color. Then after about 15seconds the screen goes black for 2seconds then back to the grayish backlight color. The number lock indicator turns off and stays off yet the green indicator in the front is on still saying my power is on. I don't know what's wrong, I need help please!