Vostro 1450 N series

I pressed the power button. The big and heavy machine does not load anything on the screen and the fan just runs. Sometimes a Dell logo appears but then it disappears, but the backlight is still on. I tried pressing F2, but white and color lights starts to appear. F12 is the same but Fn, boy, the screen flashed diffrent colors along with stripes. Sometimes it beeps 5 times, sometimes 7. I really need help.