Hooking up a PS2 keyboard would be a waste of time I believe, as you are still using USB ports, and you have a known good USB keyboard, and it still does not work.
About hooking the two computers together, there is no way to do that until after you have windows running.
About the power connectors, even with just a CD drive, it might drag down the power supply, so lets try that. First, turn off the computer and unplug the power cord from the wall or the back of the computer, whichever is easier. There should be 2 maybe three connectors on the back of the drive. One of them has four colored wires going into a flat plastic connector that is white. That is the power connector. Pull it straight out of the drive. When you go to put it back in, it will only go in one way. If you look at the end of the connector that plugs into the drive, you will notice that two of the four corners are either rounded or clipped off at an angle. That way you can only put the connector in one way. Once you have it unplugged, try starting the computer again with just the keyboard connected. Let me know how it goes.
If that still didn't work, plug everything back in, and put the card back into it, and we will try using Knoppix to see if it is a hardware problem.