My store bought computer (emachines, 2004) wont start. There is no LED light when you hit the start button on the front, no noise, no nothing. The external power protector is working fine, the monitor comes on and gives the check your PC message... but nothing else. I bought another internal power supply unit and put it in the machine.... it has a toggle power switch on the back and when I hit that the power supply and fan came to life but nothing from the computer ....no light at the front power button.... no booting sounds, nada. What do I do next? Motherboard, cpu? (I will look up what they are later) . I am crazy without my computer! Thanks.