I read about someone who had a similar problem to this before buying the stv multi cart, but now I can't find the thread. Sorry in advance if this is a known thing:
I've got a known working STV Mobo (works fine with my authentic Dynamite Deka cart) with multi-bios installed. I have a naked Darksoft Multi Cart purchased from hiscoresaves, and I'm using the SD card they provided, with the latest rollup pack on it. I set the jumpers to "5" to load Cotton 2, and it remained on 2 lights indefinitely (I waited over 5 minutes, I don't have a speaker hooked up to hear the start sound play). I restarted the system, same thing.
So, I took out the SD card, reformatted it to FAT32, copied the rollup pack over again. Tried loading Cotton 2 again, no dice. I switched the jumpers to "3" to load Batman Forever, and hey, it works! The programming light goes out, power light stays on. I power cycle the system, and it boots up into Batman Forever. No sound, but that's expected.
So OK cool, let's program it to Cotton 2 again.. Nothing, just hangs on the 2 lights forever. OK cool, let's set the jumpers to 6 to try to program Cotton Boomerang... nope. OK, let's try to take out the SD card and power cycle -- Batman Forever boots up.
So, what could explain the ability to flash game A but not games B or C? Anything I can do to troubleshoot? I might have another SD card somewhere, possibly in my SNES flash cart :thinking: (which is actually currently packed away

)
EDIT: For funsies I tried loading radiant silvergun. Same deal -- two lights on indefinitely.