Marvel vs Capcom 2 Naomi stuck restarting


Hello all. I should prolly start from the beginning. I orignally got the Marvel 2 naomi setup to go into a mvc1 cabinet, with a capcom i/o board. Initially, upon throwing it in, it just worked, which i was kinda surprised by. I was honestly expecting more problems to solve before getting it working. However the other night,(a few weeks later) the cabinet randomly froze. I turned it off and on, and now as soon as the loading game text is gone, the cabinet just restarts, where it will loop this over and over. I got into the test menu, and did a rom test, where several roms showed up as “bad”. I immediately did the test again, and got different results, again with some bad and some good, but different from previous results. Im leaning towards thinking the inconsistancy in results could be power supply related??? This is my first arcade cabinet, and i really dont know much about troubleshooting or repairing them. Im posting here hoping someone with some experience could maybe lend me some insight. Im currently thinking i should try a new power supply, but my opinion is quite uneducated in this matter. Anyone got any ideas, thoughts, opinions??? Or just know exactly wtf the problem is? haha.


Got a multimeter? you want to check the voltages from your Power Supply Unit at the Naomi end of the wiring.
Make sure you got your +12, 3.3 volts and +5 volts at the right voltage. Also check the amps.

Take a look at this link for more info

P.S. Make sure the 5 volt line does not pass 5.1 volts.


I have one…somewhere. To be honest, i bought one with the intentions of learning how to use it, and just never did. So theres one in a box around here somewhere, but i wouldnt know what to do with it unfortunately. Ill find a youtube tutorial and try that when i can. Can a power supply cause roms to randomly show up as bad?


Yes a bad power supply can cause errors.

Even if I am wrong, as someone who now working on arcade hardware, you need to learn how to use a multimeter anyways.
Its one of the things you need to check and make sure. Also owning a arcade cab is alot like owning a car there sertain things you need to know.
On a car you need to know how to change a flat tire and check your oil. On a arcade cab, using a multimeter is one of those things.
its worst with pin ball machines.

Also with your rom board, make sure both the rom board and the main units electrical contact pins are clean.
Get some q-tips and rubbing alcohol and clean those electrical contacts


No doubt. Ill try to clean things up and locate my multimeter and see what i can find out. I dont think it would be a matter of dirty contacts, cause it was working fine for a few weeks until it froze. But then again, what do i know. Thanks for the info. Ill report back when i have some info.


dirty contacts would do more than you think.

dirt or oxidation on those copper contacts would restrict the flow of electricity, even stopping it.
Which means your ram cart will not work.

Think of it this way, the OLD NES lets blow into the cart to make it work trick.

You blow into the NES cart and the game would work. See Nintendo had a security lock out chip called the NES 10.
If this chip in the console can’t authenticate a similar chip in the game cart the game refuses to boot.
All it took was blocking or partially blocking the electricity going to that chip and the chip was very finicky.
And when you blew into the NES game you provide some moisture, just enough to provide a change in the electrical impedance and allow the game to boot.
by the time the moisture evaporated the chip did its job of authenticating.

The real way to get the NES cart working (other than disabling the NES 10 chip) was to clean the contacts.
Most people use alcohol and q tips, an eraser also works as its abrasive enough to strip oxidation but not to scratch the metal pins or the PCB in the game cart.

Your NAOMI rom board is the same way.


Ok so heres a little update. I dig up the multimeter and went and got a battery for it and did some tests. My 12v was like 12.8, 5v was like 5.3 and i didnt pay much attention to 3.3, i wanna say it was like 3.2. I did measure at the psu, and at the capcom io board. I turned them all down to where (i think) they should be, and the machine booted right up…once. I got in and did a rom test, and all the roms tested good. Then i restarted it to see if it would come back on, and it went back to looping after “loading game now”. Now if i go in and do a rom test, they all fail except for one, and the results are pretty consistant. I have yet to clean any contacts yet, but ill do that next. But so far, im thinking its at least related to power somehow. Any insight on where to go from here??


If it’s possible to test your cart on another Naomi setup where you can confirm everything was working beforehand, it’d probably be the next best step.

I’ve been told that turning up your 5V line past 5.25V can usually cause permanent damage to your arcade boards, but I’ve never been too keen on testing that myself. :slight_smile:


Unfortunately i do not have access to another naomi setup. But the game was working fine for a couple of weeks. It just randomly froze one day, and when i tried to restart it, it didnt seem to wanna boot.


Could be one of the other issues. There’s a guy ChannelManiac at KLOV that knows a lot about this stuff.

Sounds like it might be number #1-#3. I’ve changed my own supercaps but you’ll have to see if there’s any damage. Check by the coin battery and the IC socket around there for damaged traces.


There is a surprising lack of pictures in here… how are you powering the mother board, through the capcom IO?

Also, the very first thing you will need to purchase when you get into the arcade world is a Multimeter. Get a nice one, and learn to use it, especially the Continuity check.

based on what’s happening, it’s possible the game OR the motherboard in general is in need of repair.


Ok, so while goin to take some pics, i had to mess with it a lil. I remember reading a few things about how the cart sat in the mobo, so out of desperation i tried taking the plastic shell off of the marvel cart, and trying it. And it turned right the hell on!.. Then it restarted. I got it to turn on a couple more times, only to have it restart each time withen a few minutes. One of the times, there was no audio “capcom presents” on the demo, which i found very odd…then it froze looping a sound effect. That was the last time it turned on. I cleaned up all the contacts and whatnot, but that didnt seem to do anything. Anyhoo, heres the pics i took. This cab is a mess, cause i just got it, and am still finalizing everything before putting the back on it and pushing it up against a wall. Right now, i have the jamma and kick harness going thru the front coin door for the sake of my back.



this dont look good, maybe the loop is an infinite??


Almost. Like i said it seems to ramdomly boot once in a blue moon, but then freeze/reboot really shortly after. I havnt really messed with it any more since. Im THINKING that what happened is, when i got the cabinet it had mvc1 in it and i didnt check voltages or anything, because the cabinet was working fine. Didnt really think anything of it. So i bought the marvel 2 naomi setup, and a capcom io and hooked everything up and it worked. Again, didnt think shit of it. Then a couple of weeks later it just freezes one day while were playing it, and dont wanna do anything else but reboot after “loading game now…” Well afterwards, i finally got around to checking the volts, and they were very high. 5.3 on the 5v, which ive read a few times will kill naomi boards. Im not 100% sure what to think. Im about to get another naomi cart(at the mercy of the us mail) and test it in my mobo, and if my mobo is working, i may just buy another mvc2 cart. Like i said im not 100% sure what exactly is WRONG, or if it can be repaired, or how long it would take. If anyone has any concrete info, pls lemme know. Ive seen and am considering that, however at 75 bucks an hour, considering im not sure wtf the problem even is, i just dunno. All i know is i want my marvel back…


5.3 is too high, the voltage should never go past +5.1 volts .

Before trying a new cart or Naomi board, get your 5 volts line back into specs first.

it could be you either damaged the game cart or the mainboard (or both)


Yea, i did get my voltage back to where it should be. And i have a new naomi mobo on the way, and i just found another mvc2 for 125. And i think im about to pounce on it.