A while back I could get a Sonic 3, board only. Although it was reasonably clean, i didn't boot. While doing random tests, I tried it with a Mega Key, just like this one:
It showed a message telling it was designed to be played on NTSC systems. So, I played a little with the switches and it booted fine with all of them off. Interestingly it didn't boot alone and also didn't with a game genie.
I quickly opened the MegaKey to see what's inside and I only could find an epoxy blob, the 4 switchs and some parts marked as RPx, wich I suppose are some resistors associated on a bar. Is there anything I can try to do to make it boot alone? It's also missing all the capacitors, except the electrolytic one, could this be the problem? What capacitors are these? I think they're decoupling capacitors, but I didn't find an clear enough image to see its values, would they be 100nF (104) ones?
the 4 switchs and some parts marked as RPx, wich I suppose are some resistors associated on a bar.
RP stands for resistor pack, it's basically a bunch of resistors in a SIP package. The most common use for resistor packs is either for level conversion (like if you have a 5 volt bus but want to use 3.3 volt logic) or for bus termination (like on a SCSI bus to prevent signal reflections.) I would say it's probably used for the former purpose here, the IC under that glop top is almost certainly going to be 3.3v only.
It's also missing all the capacitors, except the electrolytic one, could this be the problem?
Without a picture of the PCB, we can't really tell you conclusively what they are, only speculate. If they're ceramic or tantalum capacitors that go from some bus line to ground, or from the power rail to ground, they could be bypass/decoupling capacitors. But if they run between other lines, they could be used for other things. Missing these capacitors could most definitely cause the game to not work. The reason why the game does work while connected to that key cart is that it may be buffering it enough so it doesn't have bus corruption.
Hi...I don't wanna say that tails help it's a bug, only that it's different and I died of a rare way after he kill the boss but Sonic continue jumping and hitted the spike ball. It's similar with the original game (last boss running) when the robot shoot the laser, if tails hit first. You fall to the pit. Because the hitbox.It's neccesary know that this can happen.