A few years ago I had bought a Duo and a CoreGrafx system off of that guy.
That PC Engine Duo gave me problems from day 1. Add to the fact that he insisted that using a Genesis 2 power supply would be just fine. That's what he provided me with.
The CoreGrafx also had problems. It looked like shit when I got it. Looked like it had been kicked to the curb a couple times.
And white screen right off the bat.
The whole experience put me right off from ever purchasing stuff from that guy.