Sega Naomi 1 with Capcom I/O Freezing

Joined
Oct 30, 2012
Posts
22
Hey Guys,

I swear I searched. I got one "american" cab with new Happ power supply, Naomi 1, capcom I/O and MvC2 cart. Worked fine for a while, but now what happens is the game can freeze at extremely random intervals. It can be right after the "loading game" screen, or after an hour.

I suspect the capcom I/O, for some reason the 5v does not go through it. Using my multimeter all I can get was a 3.27. Tried the I/O on my astro cab, and I get all the proper readings (5, 12, 3.3). Turned up the 5v on the power supply, same deal.

I can get 5v off the jamma connector. Is there something I can do to "tighten" the connection on the jamma edge? This is the best I could do in terms of troubleshooting.

Anyone else have Naomi 1 games freeze like this? Is it even a power issue? Any input is appreciated.

Thanks.
 

Tyranix95

Chang's Grocer
Joined
Jun 30, 2010
Posts
4,593
Since your Happ PSU is new: The likely suspect is the CAPCOM I/O.

I have a Happ power supply, Naomi 1, capcom I/O and CvS cart--And get the proper power readings with no game play problems.

And, my buddy has a Happ power supply, Naomi 1, capcom I/O and MvC cart--And he gets the proper power readings with no game play problems.

And, sounds to me, like when you test your MvC setup with a different I/O, your NAOMI setup works fine.

But, the only want to know for sure is to test your setup with another CAPCOM I/O.
 
Joined
Oct 30, 2012
Posts
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Since your Happ PSU is new: The likely suspect is the CAPCOM I/O.

I have a Happ power supply, Naomi 1, capcom I/O and CvS cart--And get the proper power readings with no game play problems.

And, my buddy has a Happ power supply, Naomi 1, capcom I/O and MvC cart--And he gets the proper power readings with no game play problems.

And, sounds to me, like when you test your MvC setup with a different I/O, your NAOMI setup works fine.

But, the only want to know for sure is to test your setup with another CAPCOM I/O.

Well the I/O works fine when I put it in another cab. That is why I was thinking it was the either the PS or something in the JAMMA wiring.
 

BIGTIME

Galford's Armourer
Joined
Mar 19, 2010
Posts
470
Could be bad buffer chips in the game. I had a Giga Wing 2 cart do this to me and I had to send it off to Ken at http://www.irepairsega.com/conact_info.html to fix it.

+1 on this naomi carts were made with substandard fairchild buffers that according to Ken are like a time bomb. Usually carts just die but I suppose the buffers could cause your symptoms. The best thing ti do would be to consult Ken he is definitely the authority on sega arcade hardware repair.
 

Tyranix95

Chang's Grocer
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Posts
4,593
If you think the MvC cart is causing your problems, then put a known good test cart on your NAOMI setup with the CAPCOM I/O. Run it in your cab: See if your NAOMI setup freezes up.

---

Another option: Test your NAOMI with a SUN psu. The sun has voltage pots to adjust the +5V & +3.3V lines. Set the power to lines to 5v and 3.3v dead on (voltage measured at the power connectors on the Naomi Filter board).

---

A bad cart should not change the voltage comming from the I/O to the Naomi Filter board; however, either a bad I/O<>PSU powoer set-up should.
 
Last edited:
Joined
Oct 30, 2012
Posts
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I got two cabs giving me the same problem, but only one I can test. The other is at a friend's crib. Both are Naomi 1 with MvC2 carts.

The one at home works fine when I power it with a sun PSU. The other I will try another cart and see if it still freezes. That is why I suspect wonky power. These goddamn american cabs have been converted 7 times by the time I get to them.
 
Last edited:

skate323k137

Professional College Dropout
10 Year Member
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Can you clarify this:

I suspect the capcom I/O, for some reason the 5v does not go through it. Using my multimeter all I can get was a 3.27. Tried the I/O on my astro cab, and I get all the proper readings (5, 12, 3.3)

Are you checking the output of the capcom I/O where you'd hook it to the NAOMI to power the naomi? If theres an issue with the 5v passing through to that connector, or the 3.3 doesn't read right, you may have a bad IO or bad voltage regulator(s) in the capcom I/O. If the power output of the I/O is OK in other cabs, then it's probably the power supply you're using. Since JAMMA PSU's are a dime a dozen, I'd change that first.
 

Tyranix95

Chang's Grocer
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Posts
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The Capcom I/O also converts +5V to 3.3V, for the NAOMI. So, +5V, +12V passes thought, but, 3.3V is converted on the I/O.

(The big problem with the C-I/O is that it only supports the Naomi CN1 power plug, which is not enough to power a either a NET/DIMM or GD-ROM expansion setup.)

The C-I/O CN1 can power the a Naomi cart setup just fine--if everything is working ok.

So, you may also want to meter the power at the C-I/O connector and make sure the C-I/O is putting out +5.0 and +3.3V.

Also, you may want to meter the +5V (Jamma Harness) power lines powering the C-I/O. Make sure the C-I/O is getting enough power. The C-I/O should be getting +5.00V~+5.10V. Do not exceed +5.25V.

And if you do adjust the voltage, make sure the C-I/O +5V input voltage does not exceed the 5.00~5.10~5.20 range; and, the C-I/O output voltages does not exceed the +5.0V, +3.3V mark.

NaomiPowerPinout.gif


1. Not Used.
2. +3.3V (orange)
3. +5V (red)
4. +12V (yellow)
5. GND (black)

capcom-io-board.jpg

pinout.png
 
Last edited:
Joined
Oct 30, 2012
Posts
22
Can you clarify this:

I suspect the capcom I/O, for some reason the 5v does not go through it. Using my multimeter all I can get was a 3.27. Tried the I/O on my astro cab, and I get all the proper readings (5, 12, 3.3)

Are you checking the output of the capcom I/O where you'd hook it to the NAOMI to power the naomi? If theres an issue with the 5v passing through to that connector, or the 3.3 doesn't read right, you may have a bad IO or bad voltage regulator(s) in the capcom I/O. If the power output of the I/O is OK in other cabs, then it's probably the power supply you're using. Since JAMMA PSU's are a dime a dozen, I'd change that first.

I am checking from the I/O connector that goes into the Naomi. Had a friend of mine recently re-do the powersupply, but it could just be the extremely crappy jamma connectors/wires.

The Capcom I/O also converts +5V to 3.3V, for the NAOMI. So, +5V, +12V passes thought, but, 3.3V is converted on the I/O.

(The big problem with the C-I/O is that it only supports the Naomi CN1 power plug, which is not enough to power a either a NET/DIMM or GD-ROM expansion setup.)

The C-I/O CN1 can power the a Naomi cart setup just fine--if everything is working ok.

So, you may also want to meter the power at the C-I/O connector and make sure the C-I/O is putting out +5.0 and +3.3V.

Also, you may want to meter the +5V (Jamma Harness) power lines powering the C-I/O. Make sure the C-I/O is getting enough power. The C-I/O should be getting +5.00V~+5.10V. Do not exceed +5.25V.

And if you do adjust the voltage, make sure the C-I/O +5V input voltage does not exceed the 5.00~5.10~5.20 range; and, the C-I/O output voltages does not exceed the +5.0V, +3.3V mark.

NaomiPowerPinout.gif


1. Not Used.
2. +3.3V (orange)
3. +5V (red)
4. +12V (yellow)
5. GND (black)

capcom-io-board.jpg

pinout.png

I did adjust the knob to up the 5v, since I am still suspecting power to be the issue. However even after upping it I only got a 3.27 reading, nothing for the other two lines.

Thanks for the input guys it really helps to narrow down the troubleshooting.

I will have my friend re-check the power situation on my cab at home, and on the other have my friend swap the cart to see if it still freezes up. It sucks having cabs at different locations that need troubleshooting.
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
Where exactly does the +12v line go from pin 4 on the capcom i/o?
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
See post 11.

It's a straight tough power cable.

Post 11 doesn't help much. I'm trying to make one of these for a friend which is why I have no idea where the other end of the +12v line goes. According to the pinout in post 14, +12v line is just floating as it doesn't connect to the 6 pin connector.
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
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In this picture it connects to the other or is this a different cable?:

MVC2SetupJPGcopy.jpg
 

channelmaniac

Mr Neo Fix-it
15 Year Member
Joined
Nov 29, 2005
Posts
4,275
You said you cranked up the voltage on the PS. This WILL damage those tiny buffer chips on that particular game cart and the result WILL be random freezing. You NEVER turn the voltage up past 5.1v on the power supply when dealing with Sega Naomi systems.
 

Tyranix95

Chang's Grocer
Joined
Jun 30, 2010
Posts
4,593
Also what gauge wire if you can. Thanks.

16 AWG wire. 27" long, from Housing to Housing. Strait Through Pin Out.

IMG_0341_zpsf7a6eb14.jpg


Housings.

Top Row:

IMG_0342_zps3531fef6.jpg


Bottom Row:

f4f4f94c-6909-4d55-8c03-90cd083b752a_zpsf63963f4.jpg


Housing Connected to Capcom I/O.

Top Row:

IMG_0346_zps358f5420.jpg


Bottom Row:

IMG_0345_zpse26b43ea.jpg


Housing Connected to Naomi.

Top Row:

IMG_0347_zps61cf5df6.jpg


Bottom Row:

IMG_0348_zps2bdc0c2c.jpg


Pin Out.

JSTPinout.jpg


8 Pin Housing.

Top Row:

Pin 1: +3.3V (Brown Wire)
Pin 2: +5V (Red Wire)
Pin 3: +12V (Yellow Wire)

Bottom Row:

Pin 4~7: GND (Black Wires)
 
Last edited:

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
So just to confirm, for a Capcom I/O cable I am only looking at the 8 pin plugs not the 6 pin? So it's just 8 to 8 and not 8 to 6, correct? I think that was what confused me, I thought it was 8 pin to 6 pin.
 

Tyranix95

Chang's Grocer
Joined
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Posts
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So just to confirm, for a Capcom I/O cable I am only looking at the 8 pin plugs not the 6 pin? So it's just 8 to 8 and not 8 to 6, correct? I think that was what confused me, I thought it was 8 pin to 6 pin.

The Capcom I/O only uses 1 Power Cable. The cable has one 8 Pin Power Housing on each end. And one end connects to the 8 Pin Power Header located on the Capcom I/O, and the other end connects to the 8 Pin Power Header located on the Naomi Filter board.
 
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