Naomi Sega I/O "Rev B" 838-13683-93 6th button issue

Hi. Lots of Sega I/O related threads. Lots of "kick buttons" related issues. Not one solution.

Here's the thing. I'm trying to get the 6th button to work with a Sega I/O Rev B, 838-13683-93, well, at least it is what it says on the sticker.
Before proceding, I DON'T WANT TO USE A CAPCOM I/O (looks like it's a recurring answer). I have one. And it works fine (albeit I find it a little bit more laggy than the sega one), but it's not the case here

Whenever a try to switch the Jpn1 thing (to make the 6, 7 and 8 buttons output on the far left connectos), it kinda works... but it works like it's stuck

Like so

(looks like the 7th button on the player 2 side's stuck as well

Tested with both Naomi 1 and 2.

I could try to live with it, but I'm planning to sell the Naomi 1 with the Capcom I/O, so, I would need the Sega one working... but don't know now if it's an issue with the I/O or, something I missing.

PLEASE, HELP ME, if you can

Could be the pullup resistor is bad or the IC that handles those inputs is bad.

Xian Xi said:

Could be the pullup resistor is bad or the IC that handles those inputs is bad.

Click to expand...

Much thanks Xian! That sucks if it's that. I could try to mess around, swapping resistors...

I don't understand much about Naomis, and its pinout, but, Since I use it with a vga monitor (not a jamma cab)... couldn't I just wire the controls directly to the board? If so... is there... a pinout... guide somewhere?

Thanks again!

There is indeed a pin out.

kaicer said:

There is indeed a pin out.
View attachment 27373

Click to expand...

Thanks man. The only problem I see is... this would work with a Sega Naomi dedicated cab control panel... I wish there could be a way to simple wire an arcade stick to the Naomi mobo (like a supergun). There are several pins... I know that some are to connect a Dreamcast controller. Well, I could try to find a DC control port board and wire to it, so at least Capcom games that use 6 buttons I could use it that way (since I heard there are few that support this feature, Capcom ones included).
Which games, besides the Capcom ones, uses 6 digital buttons anyway? Hmm... that could be an option.

Thanks again!