Ok, I'm Stumped. I have a Dimension 4700 that works fine but when I turn it off it will not start (not even post) If I try to turn it on right after shutting it down, the case fan starts very fast but the system will not post. If I wait for about 3 minutes after I shut it down then it starts up without a problem. What's going on??? I have tested the power supply, RAM, and removed all of the peripherals and nothing changes. I have also cleaned out all of the dust and checked for excessive heat but nothing seems to warm and this is the only thing I can find wrong with the system. I'm at a loss. Any help would be greatly appreciated.