MVS on Astro Jamma problemo

Hey hey,

here's the deal. Sold my old neo-geo cab on these forums a couple of months ago as I waited for a Sega new astro city to arrive from HK. I'd had a bunch of problems with the six slot board in my old cab so sold that and bought a nice four slot off ebay.

I tested the four slot in my old cab with a varity of carts and had not one issue.

Then sold my cab and waited. for the new one to arrive

Now my new astro has arrived. It came wired for system 2 so yesterday I had a guy over who rewired it for jamma. It works beautifully with a system 10 jamma board as well as my st-v motherboard.

However my neo board will not play. I get sound but the picture is so badly garbled there's nothing but black and a few lines. Also- whenever a neo cart fires up instead of the normal intro jingle the music is messed up and plays a completely different melody. Its very bizzare.

So- my question is- is there some kind of connection on my jamma loom that was made yesterday that's missing for MVS stuff or is the connection identical for jamma and mvs? Is my board buggered?

I've tried a bunch of carts and the board has all been cleaned with isopropyl.

any help gratefully received,

goz

MVS boards are stereo while jamma boards are mono so if the cab is wired for mono and you want to make it compatible with MVS you have to rewire it (you can put a stereo/mono switch for full compatibility).

Power and video on the other hand are wired the same for jamma and MVS so you should get a picture. MVS boards are by no means picky about voltage so I would exclude that. If you're totally sure it's not an issue with the MVS mobo (dirty contacts, carts inserted incorrectly, etc.), then it may have something to do with the rewiring this guy did to the cab. Can you post pics of the harness?

Here's a close up pic of the loom: any ideas?

http://www.btinternet.com/~gozaimas/files/pics/Cab/loom.JPG

The connector is keyed (with a stopper on pin 7) or it can be plugged in upside down? Because if it's inserted the wrong way you'd get no picture (and sound) and the board could get damaged. Make sure the side with the red arrow is up.

There's no stopper on 7 but I have been inserting the loom the correct way up.

As I can get two other jamma systems working fine on the cab I presume its tI presume that means its the actual MVS board that is in trouble yes?

EDIT: its only a three button cab (per player)- i take it this wouldn't be the problem though?

goz

ey up Si,

if its working okay with normal JAMMA games, then I would hazard a guess its because of the slight differences for the MVS wiring (normally stereo speakers, butons 4 per player and the SELECT button which is usually button 5/pin 26 on a JAMMA loom)

is your astro wired for MONO or Stereo ?

Hey Mark,

Just sent you some piccys as requested by the way.

In terms of the wiring- not sure if its wired for stereo- I think its just mono from the board tests I've done...

Would that effect the picture?

well, JAMMA is MONO - MVS is stereo

infact . . hardmvs says about all this

http://www.hardmvs.com/html/jamma.htm

you've got a 4 slot right ?

personally myself - I think your going to need a 1 slot

hardmvs website said:

Q: Will the motherboards work in a JAMMA cabinet?
A: They will all work, but are not 100% JAMMA compliant

Q: What does that mean?
A: The 1 slot boards are the closest to JAMMA, but have the addition of a 4th button. Some of the 1 slot boards have an external connector to run Stereo sound instead of the mono JAMMA sound

Click to expand...

http://www.hardmvs.com/html/MVSfaq.htm

btw - check your e-mails

crap- is there any way to wire my astro loom for both tghe 4 slot and jamma boards or is it one or the other?

(resent images without mac comporession this time)

personally myself mate, if your wanting to use your cab for a variation of games that are mainly JAMMA then i'd go fo the 1 slot, all you need is a button 4 wiring in, I suppose you could make a JAMMA - MVS adaptor of some sort tho

The slight differences between the MVS and Jamma pinouts are irrelevant to the problem you're having. An MVS board in a jamma cab would display the picture 100% correctly.

even tho the Astro is more than likely wired to JAMMA + standard ? ?

As for the sound issue, you can make a cab compatible with both jamma and MVS if you add a switch wired like this:

http://www.neo-geo.com/forums/showpost.php?p=1268981&postcount=28
(it's important that the speakers are 4ohm)

MKL said:

MVS boards are stereo while jamma boards are mono so if the cab is wired for mono and you want to make it compatible with MVS you have to rewire it (you can put a stereo/mono switch for full compatibility).

Power and video on the other hand are wired the same for jamma and MVS so you should get a picture. MVS boards are by no means picky about voltage so I would exclude that. If you're totally sure it's not an issue with the MVS mobo (dirty contacts, carts inserted incorrectly, etc.), then it may have something to do with the rewiring this guy did to the cab. Can you post pics of the harness?

Click to expand...

"MVS boards are by no means picky about voltage so I would exclude that"

Click to expand...

"In general"
Are you sure about that above statement..?
I've read many times that "6" slot MVS boards are picky about voltage.
An older 4 slot mother board IMO could be subject to the same and need just a tad more voltage to run right..
As parts/caps etc get older..

If I dip my Big Reds voltage just below 5 volts I get a garbled picture then no picture/black screen.

Now with gozaimas problem..
I figure he must have a wiring mixup..Well,with the way it sounds he definitely needs to switch the wiring to stereo/or put in a switch method or just buy a 1 slot
But,we have no clue just what his power supplies voltage is set at..
It may be just a bit to low....
The jamma boards he has just may run on the current voltage it's set at...it may just be too low.
I've ran Jamma boards on less then what my MVS required..

Unless he is able to measure that voltage he's not going to know..

I'd also clean the edge connector on the 4 slot plus the cart slots and carts..
But I'd use something a bit more stronger to clean the carts connectors and edge connector..
Something like very fine sand paper or dry green Scotch Brite.
These connections may just be too dirty and not making a good connection..

chris1 said:

"In general"
Are you sure about that above statement..?
I've read many times that "6" slot MVS boards are picky about voltage.
An older 4 slot mother board IMO could be subject to the same and need just a tad more voltage to run right..
As parts/caps etc get older..

If I dip my Big Reds voltage just below 5 volts I get a garbled picture then no picture/black screen.

Click to expand...

While I'm typing this I have my 4-slot (older type) running at 4.54v with all carts in. No garbled gfx, no problem whatsoever. And it's always been like that for any other MVS board I tried. So yes, MVS is by no means picky about voltage period. I could quote posts by Nightmare Tony where he said this same thing.

From my experience with 6 slots, anything less than 5 volts = no boot.

My Astro city Power suppy have 7Amp only on 5Vline maybe the MVS four slot require 10Amp minimum.
MV1-F (one slot) work perfect but I have not tested a four slot on this cab.

mukuro said:

MV1-F (one slot) work perfect

Click to expand...

I prefer 1 slots anyway

MuKuro said:

My Astro city Power suppy have 7Amp only on 5Vline maybe the MVS four slot require 10Amp minimum.
MV1-F (one slot) work perfect but I have not tested a four slot on this cab.

Click to expand...

hmm- could you just explain that a bit more to me?

I guess the only way I'm really going to know if its the wiring or the board is by testing my 4 slot in another cab/ supergun...

Volts....

A 7 amp power supply is more than enough to power a 4 slot, I have powered them with a 4 amp supply no problem....
As for voltage I run my 6 slot boards on 4.8 V no problem..
I have run 4 slot boards with 4.5 V at the jamma terminals perfectly...

MVS is by no means picky about voltage period.

Click to expand...

In General..

People's experiences with this problem goes both ways so "I" can't say who is right or wrong...

I've ran into this problem many times..I've sold-owned/own-tested many MVS boards.

I can go lower my cabs right now below 5V and they won't boot,give garbled graphics,show no picture etc...If set to low it shuts down..(this may just be the boards I'm running/ran into and the power supplies I use/used)
It depends on how low I go with the voltage.....(testing it with two separate meters getting the same reading)
If I run my Big Red with the voltage meter reading the voltage at the rail and lower the voltage to around 4.7V the screen will start to get garbled go a tad lower and the screen goes black,no boot..


...(I also think it depends on the particular power supply that is being used /for me.)
In my Bam MVS cab I have a standard type Peter Chou power supply that is set at 5.05 and it will only run at that for the 1 slot MVS.
If I run it fine,below that the boot Puzzle Bobble sound will cut out..either during the demo or upon power up.
But the Taito F-3 motherboard in this cab with the MVS will run no problem if I leave the power supply set at 5V even.. or even lower.
So is it the Boot PB cart that's requiring more Voltage?


From all my experiences/people I've helped here it's still a possibility to me that MVS can be picky about voltage..
There are threads whereas this was the problem...
I myself was going through a problem with the Big Reds old power supply..(awhile back)(threads to old to locate)
The power supply was bad and had to be set at a higher voltage to run the cab...I was well above 5V (too high)with the voltage reading and the power supply had a buzz.(I was told I should not run the cab at the voltage it currently was at and may cause damage to the MVS board/To get a new power supply.
When I would turn this power supplies voltage down the screen would start to show lines and get a bad picture,go garbled then black.
Only turning it above 5V would show a clear screen.
This also caused certain cart mixes not to boot etc..just a major headache with that power supply.
In all honesty..I wanted to play the cab so bad that it ran like this for the longest before I realized something was wrong/heard a buzzing in the power supply and decided to take a voltage reading...(asked about it here)
I didn't know what I was doing at the time and came to realize that if I left the voltage that high I could of screwed up the board in the cab.(after coming here)

I replaced the power supply with the original type/new power supply and the cab will run straight 5v(perfect) but it has to be 5V.
The old power supply would not work at 5V...it needed more voltage to work.
Now that was a power supply problem...but,I still had two different voltage requirements to run the same board.
What explains that..?

Some power supplies just may be worn out..
Something in that power supply needed to be set higher to run the MVS board.


I have a spare power (big red type)..if I plug it into my Neo Gold (2 slot)and turn the knob down to just below 5V it cuts out/shuts down..
It will not power up the cab unless it's set above 5V..The power supply just shuts off.
I have to turn the knob back to 5V and flip the on/off switch..

I don't know what's wrong with it and I can't clearly see anything wrong as it looks new and it's the same type power supply I have in my Big Red.
This is a power supply problem,not MVS....but to run the 4 slot it has to be at 5V with this particular power supply.


............................................................................................
What about the threads whereas tweaking the power supplies voltage a bit more helped to run certain games that would not run on 4 to 6 slot MVS boards?


..
In General...What I state does not mean that IT'S NOT possible that a MVS board will run at a lower voltage...So I'm not saying anyone is wrong by their statements but to look at it with an open mind.

I think it's possible...No point to argue about it..



........................................................................................

I have no clue to the condition of the gozaima's MVS board or Power Supply.
Neither do I know what voltage he is running at.

IMO..It's possible that if his power supplies voltage is too low it may not run his board.