Why does HP Laptop screen goes black after the logo?

When starting my hp dv9000 it goes to the HP Logo screen like normal but once that goes away the screen just goes black and does nothing. I hear the fan running all the led’s on the laptop are lit up except for the hdd light on the front of the case. I’ve tried the pull out battery unplug power adapter hold down power button thing still same thing. I’ve also hooked up an external monitor and it does the exact samething. Brings up HP logo screen then goes black. Any suggestions?