Well I'm happy to report that all is well and it doesn't appear to have been the dc jack.
I went through the list as you suggested and there was no change. I was a bit frustrated at that point so I
proceeded to disassemble the entire computer. As it turns out, it was very dirty inside and the fan and heat sink were totally clogged. I cleaned the inside of the case, took out the LCD screen, cleaned it and reassembled the laptop. I took great care to double and triple check every connector and that every screw was in place.
Once back together, I pressed the power button and "Voila" she boots up perfectly.
Thanks so much for your time and help. I needed a patient voice to talk me through the troubleshooting process. Otherwise, I may have thrown the thing down a flight of steps.
LOL, thanks again.