The black screen of death and no plugging unplugging would work

Hello,
My Toshiba AMD C600D-01L is turning but not working (?). I can hear the fan running, the DVD light is blinking at the side and the green light turns on but the screen is black. 1) I tried shift F8+ power button and 2) unplugging and removing battery, pressing power button for 60s then plugging in and still the black screen is there.
I had sent it for repair only 10 days ago and it had the same problem before repair. I need to know what's wrong and what I can do to repair it. Please help!!