I found this thread as I was having the same problem.
I have a 40 inch lcd Samsung screen and could not get the virtual console to work at all except for the home menu.
The screen was just black. I tried a few Megadrive and Master System games.
However, holding the keys in the operations manual worked for me and now all the games work fine.
Thanks a lot OccasionalGamer for sharing the fix!
I have a component cable which is 20 metres as the TV is on the other side of the room over the bed!
P.S. Why do you limit usernames to 10 characters on this board?