Naomi -> Sigma AV7000: Help Needed

OldFoo · Post by **OldFoo** » Sat Mar 03, 2012 11:45 pm

Hey there,

I just picked up a Sega Naomi mobo and Capcom I/O.

This is my first time setting up anything other than MVS or CPS-2 on my Sigma, so I have a few questions before I blow anything up. From what I understand, using a Capcom I/O should allow me to draw power directly from the supergun, but I'm not getting audio or video at the moment. I can hear the fan, so it is receiving power. On the video side, I'm connecting to a PVM via S-video, which works fine with CPS-2 stuff so far.

Here's what it looks like right now, in terms of connections (though not in this picture I DID have my a/v cord plugged into the AV7000:]):

First, do I have to adjust anything on the Supergun end in order to get the Naomi up and running? I seem to recall reading to adjust the 5v pot up slightly in the 5.25-5.1 range, though I'm not certain.

Second, do I have the proper power cable?-- I notice some setups that use the connector to the left of what I have used. I believe its only for the GD unit but I'm not positive.

I'm at a loss, and don't want to wreck anything being hasty. Do your worst friends.

Edit:

I have used a multimeter to measure the power coming off the I/O:

I have found the 12v and 5v lines reading correctly, but the next one, which I assume should be 3.3v, is reading 0v. Does it sound like I need to be using another PSU instead?

OldFoo · Post by **OldFoo** » Sun Mar 04, 2012 9:07 am

No 3.3V = no Naomi as it it needs 3.3V

Sounds like either the wiring is not 100% or the Capcom I/O is not 100%

OldFoo · Post by **OldFoo** » Sun Mar 04, 2012 4:21 pm

Thanks for your reply.

Does it make sense that no power to the 3.3v line would yield a Naomi that powers up with Fan and LED lights but NO video or sound? This is what I am up against right now.

Now, I've tried various combinations, but I believe I have it setup correctly for my application (supergun to Sony PVM via S-video)-- 15hz dipswitch set on the mobo, and Composite sync on the Capcom I/O (with the other option being separate H/V sync)

OldFoo · Post by **OldFoo** » Sun Mar 04, 2012 6:26 pm

eczangief wrote:Thanks for your reply.

Does it make sense that no power to the 3.3v line would yield a Naomi that powers up with Fan and LED lights but NO video or sound? This is what I am up against right now.

Now, I've tried various combinations, but I believe I have it setup correctly for my application (supergun to Sony PVM via S-video)-- 15hz dipswitch set on the mobo, and Composite sync on the Capcom I/O (with the other option being separate H/V sync)

The fans run off of 12v directly from the power supply.

OldFoo · Post by **OldFoo** » Sun Mar 04, 2012 7:08 pm

Thank you kindly! Okay this is starting to make sense, slowly but surely.

I'll be looking into another PSU to use instead. I will update this thread as I progress.

Thanks again for helping out a new member!

OldFoo · Post by **OldFoo** » Tue Mar 06, 2012 1:46 am

If you have a volt/multimeter, you can verify if the power supply is sending 3.3v or not. Since there are many JAMMA boards that require it, I find it hard to believe that it is not supplying 3.3v. Check both before and after the Capcom I/O.

OldFoo · Post by **OldFoo** » Tue Mar 06, 2012 2:12 am

I went out and picked up a decent multimeter to double-check my readings, and with my new tool I was able to confirm that the Capcom I/O is putting out 3.3v (read exactly 3.30), in addition to the 12v (read 11.80) and 5v (read 5.15).

My power supply is built into my supergun (Sigma AV-7000), it outputs 12v, -5v, and 5v-- I was under the impression that the Capcom I/O is able to take power from a typical arcade PSU like the one built into my supergun and output 3.3v. Am I correct there?

In my limited understanding it seems to me like the Capcom I/O is behaving properly and that my Naomi mobo is now the likely problem.

I'm concerned I may have blown something, because when I measured the 5v line coming out from my supergun I got a higher reading with my new multimeter (I think it was close to 5.4 or 5.5v and I have read that 5.2 can cause major problems with the mobo).

Is there something I should check out on the mobo to see if anything has been fried?

Thanks to everyone whose weighed in so far.

OldFoo · Post by **OldFoo** » Tue Mar 06, 2012 9:06 am

eczangief wrote:I went out and picked up a decent multimeter to double-check my readings, and with my new tool I was able to confirm that the Capcom I/O is putting out 3.3v (read exactly 3.30), in addition to the 12v (read 11.80) and 5v (read 5.15).

My power supply is built into my supergun (Sigma AV-7000), it outputs 12v, -5v, and 5v-- I was under the impression that the Capcom I/O is able to take power from a typical arcade PSU like the one built into my supergun and output 3.3v. Am I correct there?

In my limited understanding it seems to me like the Capcom I/O is behaving properly and that my Naomi mobo is now the likely problem.

I'm concerned I may have blown something, because when I measured the 5v line coming out from my supergun I got a higher reading with my new multimeter (I think it was close to 5.4 or 5.5v and I have read that 5.2 can cause major problems with the mobo).

Is there something I should check out on the mobo to see if anything has been fried?

Thanks to everyone whose weighed in so far.

There's a potentiometer or adjustment knob on most power supplies to turn the 5v down. Find it (if yours has one), and then then it down till you get around 5.1

OldFoo · Post by **OldFoo** » Tue Mar 06, 2012 12:32 pm

I was aware about the pot to adjust the 5v line on my supergun, I'm afraid I was upping it based on readings from an antiquated multimeter. Now I've got it down to 5.15 or so.

OldFoo · Post by **OldFoo** » Tue Mar 06, 2012 5:06 pm

One thing I learned the hard way, make sure you check the voltage readings under load. They'll be different when the PSU is hooked up to something.

Also, There's nowhere on a JAMMA harness for a 3.3v line... not sure how he could check before the capcom I/O unless his PSU outputs 3.3v directly, but even then, it wouldn't be hooked to the JAMMA harness on the I/O.

The capcom IO creates the 3.3v for you by converting voltage internally. If you have 5 and 12v into the capcom I/O, but no 3.3v out, it's probably the I/O (or voltage regulators inside of it) that is the problem.