What does it do when it doesn't work? Does it just not boot, or does it just work like shit? Mine basically acts like a dead HuCard.
On my Duo it will load the menu and load most games. You then play the game and after about 30 seconds to 1 minute the graphics just fall apart and eventually everything freezes. It also seems to actually corrupt the information on the flash drive. When I would take it back to my PC to reflash sometimes my PC could not read the data on the card until I formatted it again. On the my $15 Turbo Grafx the exact same game plays fine. I played all the way to level four on Legendary Axe II with no problems. Each time I reflash the PC reads the card just fine.
Here is an example of the problems on the Duo with the flash card:
I have a lot less knowledge of how these consoles work electrically than most of you guys do. I would love to know more about where this +5 volt rail is located and a method of supplementing it with power. I'd love to test that out and see if it really works. The most sophisticated thing I've ever done is recap a few Dell motherboards, computer power supplies, and a few DVD players. So I know my way around enough not to be electrocuted and that is about it.
However, I just remembered something and thought I should point this out...
The Turbo Grafx is using the original AC Adapter which is 10.5 V and 730 mA, the Duo is using an AC adapter that is 10 V and 2000 mA. That might not mean anything but there is a difference of half a volt there. I know this has pretty well been ruled out, but just so I can witness it myself I might see if I get different behavior on the Turbo Grafx with a different AC adapter.
Okay. Tried 9 volt, 12 volt, 10 volt AC adapters. All with mA over the original Turbo Grafx range. No difference with the flash card on the Turbo Grafx. It always works. It must be internal to the Duo and Turbo Grafx.