Hi!
Tested some more, here the results:
As USA didn't work all I've tried are Japanese roms:
1943 Kai (J).pce WORKING
Adventure Island (J).pce WORKING
Aero Blasters (J).pce WORKING
Alien Crush (J).pce WORKING
City Hunter (J).pce BLACK SCREEN
Dai Makaimura (Super Grafx) (J).pce BLACK SCREEN
Darius Alpha (J).pce BLACK SCREEN
Darius Plus (Super Grafx-compatible) (J).pce WORKING BUT SCROLL GARBLED IN A LINE UPSIDE OF THE SCREEN
Devil Crash - Naxat Pinball (J).pce BLACK SCREEN
Dragon Spirit (J).pce WORKING
Fantasy Zone (J).pce WORKING BUT SHAKING SCROLL

Final Lap Twin (J).pce BLACK SCREEN
Final Soldier (J).pce WORKING
Final Soldier (Special Version) (J).pce WORKING
Gradius (J).pce WORKING
Gunhed (J).pce BLACK SCREEN
Jackie Chan (J).pce WORKING
Kiki Kaikai (J).pce BLACK SCREEN
New Zealand Story, The (J).pce WORKING GARBLED GRAPHICS SOUND OK
Ninja Warriors, The (J).pce BLACK SCREEN
Pac-Land (J).pce WORKING WEIRD CONTROLS
Raiden (J).pce WORKING
Salamander (J).pce WORKING
Skweek (J).pce WORKING
Super Star Soldier (J).pce WORKING
Terra Cresta II - Mandoraa no Gyakushuu (J).pce WORKING
Volfied (J).pce WORKING GARBLED GRAPHICS
Seems far more stable now trying only japanese roms

Regards.