If you start the computer (Does it beep at you) if so then it is the ram. I had the same problem with my old Hp computer.
Will the computer start at all?
Was there anything spilled onto the computer by any chance?
Does you mobo get any power to it?
If you get no power to the Power supply, then it's a bead Power supply.
If you get power to the power supply and not the mobo then your mobo is dead.
If some one kicked or tripped over any cords to the tower, it could have caused a short and fried something within the computer... Either that I would check and see if the switch to the power supply was tripped to off
(Had to point that out)