Because all 3 Jaguars with two jagGD gave the same red screen problem, I used several roms including an internet archive fullset that says it is 100% compatible with jagGD, other roms I hunted on the internet and also the 3 roms made available by stoneage gamer for whoever bought the flashcard there, all gave red screen. The memory test was successful as no error message appeared on the screen. Tested with original console source and quality parallel source, I used scart cable, composite cable and s-video cable, I used contact cleaner on the slot yesterday and today isopropyl alcohol to brush the contacts with a brush. All gave red screen. With genuine cartridges this problem does not occur. I'm actually pretty worried.