I'm installing the ST-V multi for a forum member and I'm really struggling with it somehow, don't have a ST-V myself so cannot compare.
I did install the cart, LCD selector, reset wires and sound wire, and the motherboard has a fresh battery and modbios if that matters.
Modbios is v1.11 and default set to Japan
My symptom is that when I select a game on the LCD and start it, I do hear the 'SEGA' sound via the sound mod and it reboots, but the screen stays black.
After selecting the game again on the LCD I get 2 options depending on the game:
1. It reboots, shows the cart name on top of the screen and loads the game (this happens on very few games)
2. It reboots, show a check cart connector and press service to exit message, if I press service now, it boots to the ST-V post screen as if no cart is installed
What I tried so far;
1. reseating the cart
2. formatting the SD and loading the latest Smokemonster pack
3. Re-flash the Arduino with the file included in the Smokemonster pack, v.3.0C IIRC
Not sure on the cart firmware, but it was purchased last year so this should be the latest right?
This is how the reset wire is installed;