Flashing power light

that means STAND BY MODE...

Go into your system bios and your computer settings...

Change - Push power = power save or Hibernation mode to Push Power = OFF

In windows, right click desktop, goto properties... Click the screen saver tab... Should be an advanced option or power mode button. click them. Disable hibernation and change the setting that says:

When I push the power button, sleep mode or whatever to:

When I push the power button, turn off computer.

I thank you for your help, The computer does not let me go into the BIOS. That is why I am mystified, because it will at least let you get that far, but it is not. Do you have anymore other thoughts? I would appreciate anything else you could think of.

Open the PC and find the BIOS chip. See who made it and find out if the have a flash utility on their website. You could also remove the battery(on the motherboard) and set the jumper (near the battery usually) on pins 2&3. Put the jumper back on pins 1&2 and replace the battery. This will clear out the CMOS settings and allow you to get into the BIOS setup.

Start at the beginning.
disconnect all power leads to drives etc, and just have the motherboard power plugged in.
We are trying to ascertain weather its a psu fault or something else. If it comes on ok, then one by one reconnect every power connector, till you find the offending bit. You have to have the motherboard plugged in as it acts as a switch ond the m/b wont fire up unless it is.
Try it !!