Under most circumstances, a bad hard drive would cause a Computer to start, but fail to boot up. (IE, it would display the POST messages and so forth).
However- that being said I have seen Hard drive problems confuse the bejesus out of a PC to the point of simply presenting the black screen.
I personally cannot see any harm in your idea; worst case scenario is the laptop fails to boot when the "dead" hard drive is in it. However, this brings up the question of wether the drive will fit, since desktop hard drives are too big to fit in laptops.