That's what happend:
Using the Tennis cart the screen went black after pushing the disc at the ECS start screen. Same happened using the rom on the CC3. The Tennis cart works fine without the ECS .
The Soccer cart works fine with the ECS and it asks after the game title screen for the numbers of players. I entered 2 : 2 players...and plugged in two additional contollers at the ECS.
It worked! World Cup Soccer is a 4 player game!
Edited by Intymike, Mon Jul 28, 2014 1:34 AM.