J-Pac Multi-Key issue

[kagaden]

Since I've installed my J-Pac in December, I've noticed an issue with Street Fighter type games where pressing 3x punch or 3x kicks at the same time (either player) will cause the move to not properly come out. I recently installed Street Fighter 4, jumped into the training mode, and watched the input being received and found that there's an erroneous punch or kick (respectively) just before the 3x punch/kick registers.

Actually, I don't think it's so much as erroneous, as I feel that when you press all 3 punches or 3 kicks that they're registering at very slightly different times and SF4 is merely compensating for this and inputting the 3x move right after the erroneous move. I'm going to test this on notepad tomorrow to see what's actually coming up rather than SF4's interpretation of it.

What happens in gameplay is that things like Dhalsim's ultra move (qcf, qcf + Px3) comes out as a super (qcf, qcf + px1) instead if both meters are charged. Highly annoying, I haven't dealt with it until now because I've been primarily using the cab for 3rd strike (no 3x button inputs).

About 90% of the time when I hit all three punch or kick buttons I'll get a random punch/kick (usually light) prior to the 3x input registering.

It's not only SF4 though that has the problem. Super Street Fighter 2 Turbo w/ Gief's SPL (3x punch or kick) has about the same odds of coming out (10%) as well, making me believe it's something to do with the wiring or Jpac processing itself.

Can anyone think of good ways I can test this? Or if you have an i-Pac/J-Pac yourself, someone give me a heads up on how your buttons behave?

Thanks,
-K

[Lilwolf]

Have you gone into the game setup (not sf4, but the mame versions) and gone to the button test screens?  (I actually don't remember sf's if they have one, but most do.  I usually use mk2 because it also has a good monitor grid for testing).

but if they all are showing up there on cue, its not the encoder.  try holding all down... release one... press that one back... and take one more off.  if you get visual cues syaing that they are all being pressed at the right moment... then time to just practice.

[kagaden]

Individual inputs work fine. I haven't had a chance yet to hit notepad and try the buttons there to see if I'm actually getting a rogue button press or not, but that's certainly what it looks like in SF4 on training w/ inputs turned on.

I have co-workers who are professional/tournament SF4 players in the company who actually noticed the issue long before I did. I'll get some more documentation and put it up to assist with debugging. I really have no idea what would be causing this.