My HP Compaq Presario R300Z notebook doesn't turn "ON". When I press the Power ON button nothing happens. No LEDs, no sound of the hard drive spinning up. NOTHING! I sent it in to HP twice recently and both times the system board was replaced. Why they would have to change the same part twice was curious enough, but now it's worse than before they fixed it. What items have to be functional for the POST to pass? I know the ON/OFF switch has to be able to go closed to turn on the power supply on the systemboard in order to supply juice to the BIOS so it can talk to the CPU and also tell the hard drive to start spinning. After that what happens? I don't even get the LEDs on the Power ON/OFF switch or the LED for the Hard Drive or the one indicating the unit has power and that the battery is being charged. No LEDs come "ON" at all. Could the hard drive cause this problem? If the POST passed would I at least hear the hard drive spin up and see the LEDs come on that normally lite up at startup? Thanks

Maybe the cooling fan is shot? Do you hear any fans running? My old laptop did the same thing, and since I don't know much about those, I got rid of it. Now I wish I still had it to tear apart...

Do you hear anything???