Sega-Naomi

First and foremost, you guys are all aces. Can't tell you how many times this forum has nailed questions I've had, time and time again. The gratitude is seriously eternal.

That being said, it's about time I got involved. (Thought I'd throw out a new post first, rather than start posting replies w/no credibility whatsoever, and as you'll come to find, do not have anyhow) So here's the deal:

Out of all my Naomi setup's, the only board that's ever given me hell is an MVC2 kit that's never left the cab since I bought it new years ago. About a year ago, I got a call saying the "game keeps freezing". No sweat, the power supply that was in that cab had seen better days, and was due for retirement. Slapped in a brand new Sun PSU, worked like a charm.

4 months go by. Get another call, same thing, freezing. Troubleshoot a bit, everything checks out, voltage, interchange w/different cables, mainboard, even PSU again, just to be sure. This time no fix. WTF?? Call up our buddy Ken over at ARC. (thanks to you guys for the referral) Send it off, Westerfield reps the buffers, get it back, no problems.

Then last week I get the call, again. No way! But just when I've concluded that the problem has simply escalated to "beef between me & god" status, I'm checking out the voltages, and they're incorrect! YES! So I juice it to 5.1, kick it on free play to celebrate, and haven't had a call yet. But here's the kicker - (cue theme to Halloween) -

While checking the rig with my multi-meter, I'm not sure what inspired me, but after checking the harness, stuck my probes on the JVS connector leaving the Capcom I/O. And JESUS, this can't be right! The DC voltage off the I/O is as follows:

12v = 19.xxx

5v = 7.xxx

I asked everyone in the shop if they had a multimeter in their truck/car/purse and one guy actually did. Sure enough, same thing. Not only that, but 3.3 read fine on both meters!

Now I'm no expert on voltage conversion, but to me, my discovery at that point in time roughly translated to: "F'd I/O". I never got around to trying it, but I didn't know a board could run at all, juiced like that!? Funny how all the while, it didn't even cross my mind that it could be the wonderful, perfect Capcom I/O! So lesson learned: electronics still break sometimes. Brilliant!

If you made it through this story, a testament to you. And I tell you, this isn't over. I'm repairing that Capcom I/O, even if it means I have to learn molecular physics. I'll keep you guys posted, and as always, I'm open to input from all. Aces!

Worth noting the 16bit buffer burnout issue EFFECTS ALL Naomi 1/2 and Dimm boards..



Lucky our Man Ken can fix them, but it many cases it econimical to fix. :smt009

Hi, i got a similar problem, my Capcom I/O send to the mobo 3,29 V , 5 V e 12 V are ok, i think that is the cause why when i try to run my DIMM (just the DIMM), i have black screen (with the bare mobo i have the naomi logo and then error 01, and this is ok)..



How can i increase the 3,3 V out ? I've already tried to gain the 5 V from the Jamma PSU, but no joy...



Thank you!

I got a similar problem also I think. But my NAOMI works fine on a Supergun with Capcom I/O.



Yesterday I tried it on my New Astro City Cabinet and the games freezed or rebooted all the time. I've got no power meter, but can there be someting wrong on my astro city? I dont have other arcade boards to test... When I bought it this weekend it was showed with a arcade PCB and worked fine.



I posted this problem in my own topic also. But it all seems very simular. My Capcom I/O can be broke I pressume...



Please help

First thing to do is check your actual PSU with a meter man. You can pick one up at Walmart for like $10.



Since it works fine on your Supergun, chances are its definitely your Astro's psu.



In case you're not sure how to use the meter:



Set the dial to DCV 20, then, with your Astro on, place the black lead on on grounding pin, and the red lead on a +5v pin coming off the Jamma harness. If it reads below 5.13, the astro's psu is most likely your problem. Hope that helps :]

Stories like this prove my point the Capcom I/O is overrated and overpriced. It can be nice to have but not for the going rate I've seen. :smt020

maxchainsplendid wrote:First thing to do is check your actual PSU with a meter man. You can pick one up at Walmart for like $10.



Since it works fine on your Supergun, chances are its definitely your Astro's psu.



In case you're not sure how to use the meter:



Set the dial to DCV 20, then, with your Astro on, place the black lead on on grounding pin, and the red lead on a +5v pin coming off the Jamma harness. If it reads below 5.13, the astro's psu is most likely your problem. Hope that helps :]

I had a reply on a other topic too, but I just bought a meter



The black lead on the astro grounding pin and the red lead on the backside of the jamma harness?

Nothing beats a picture eh?

(the black lead is supposed to be touching the contact under the arrow, but it's hard to chopstick the things w/one hand, lol)

thats the +12v

the +5 is pins 3 and 4

Listen to Grant, he's way smarter than me. damn chopsticking....