Capcom I/O sometime works

[XeD]

I have a capcom I/O that would sometime work. Once it's recognize It operate fine (1 out of every 10 or so). I don't think it's a psu issue because when I use another capcom I/O it boot fine.

The problem is my Naomi does not recognize the I/O spitting out a "Jamma I/O board not found"

I have clean the edge connect and it's set to 2 player. Any ideas?

 

[Asayuki]

Loose joints somewhere? Expecially look in the USB area.

 

[XeD]

Well, I finally fix this thing. It turn out to a solder bridge on the underside of the board. Pin 1 and 2 of the SOT-25 step down converter. From what I can tell its been there for awhile (factory maybe?) as the solder is dull like the rest and there is no flux residue. It would always boot on a cold start and fail on multiple reboot.

PS. I guess it help for me to get a fresh look at it after 5 month.

 

[Asayuki]

Glad you got it fixed.
Nah, factories have inspection procedures to prevent f***-ups of that magnitude. Maybe the previous owner tried something unbelievable with it and ended up damaging it without even being able to realize that.