MacBook powers on instantly when plugged in, no boot and no sounds

I have an early 2008 MacBook that works and this original model that is having the issues. I mention the 2008 model because I'm using the same power supply so I know it's a good (and have used others just to test).

When I plug the Magsafe connector to the original MacBook, it goes green. The screen has a quick flash like it just received power, and the white LED in the front is on solid. The MacBook turns on any time I connect power to it without pressing the power button.

The hard drive is spinning, but there is no boot sound or error beeps. I have tried swapping RAM (2 1GB sticks), leaving one or the other out, and even tried leaving both out which should give me error beeping and a flashing LED on the front. It just stays solid.

I've even removed the hard drive and still nothing. Both MacBooks have a non working battery. With the battery installed or not, the working MacBook gives me five flashes before the boot chime to indicate a battery issue. Again, the non working MacBook just has a solid white LED at all times.

If I hold the power button down for 10 seconds, it will turn the non working MacBook off and the front LED will go out, the power LED still stays green. Pressing the power button again will turn the front LED on solid, but no sign of booting, just the spinning hard drive. Even trying to reset PRAM doesn't appear to restart the MacBook.

It's not a loss for me if I can't get this going, but I do enjoy working on older machines and keeping tech out of the landfill if possible. Could the power connector inside the MacBook be the cause? What has me stuck is not having any beeping/flashing error "codes" to lookup, so no starting point.