4th Button Problem

Hi there

I own a old MK2 jamma arcade which comes with 6 buttons per player + start and everything runs fine.
the problem is when i use my 1 slot mvs on any neo geo game only 3 buttons are detected by the arcade + start button this is kinda frustrating as most new games require 4 buttons ;;
I was wondering if anyone here could give me some advice as to where i should start looking to fix this problem as i don't rlly know alot about these old machines and i don't wanna start poking around and damage it

Many Thx -DeN-

http://hardmvs.com/manuals/Jamma2NeoGeo4SlotPinout.pdf

make sure it's wired for MVS.

which part are you talking about when u say rewire it,

the jamma connector or the 1 slot mvs?


i tested the buttons on mk2 and my neo geo all 6 work fine on mk2 but it's the D button thats not getting picked up on my neo geo 1 slot when i tested it in I/O mode

Thx again

MK2 cabs are JAMMA+ and should be 5 buttons plus Start. You must have a conversion cab from a Street Fighter. 2/3 of the buttons are on a kick harness. So only 3 buttons are wired to the JAMMA harness. If using MVS only 3 buttons will register. You'll have to add the 4th one yourself.

If you attach a wire to pin 25 and the pin directly underneath it also on the jamma connector, this will give you your 4th button (D). All you need to do is decided what pushbutton on your panel you want to wire it to. Im guessing that your cabinet gives you 2 block buttons on mortal kombat 2 right? This is because midway recognised that MK pcbs would end up in streetfighter cabinets, hence why you get a block button from the harness and jamma+ plus loom also.

Hope that helps you.

thx for the info

after ringing up several arcade places nearby and they basicly told me to P*** off lol i decied to just take alook for myself....

after closer look i noticed that 6-8 wires that connect from the buttons go straight to the UMK3 jamma board via a seporate set of pins (not connected to the jamma harness )

so if i get this right all i hav to do is snip the 2 button wires i want and solder them to the 2x 25 pins on the jamma connecter and this is enable Button D

I took a few pics hope this helps
http://homepages.nildram.co.uk/~pjack78/rob/wires2.jpg

this pic is where the connecter came from on the UMK3 Board
http://homepages.nildram.co.uk/~pjack78/rob/wires3.jpg

-DeN-

Or instead of just cutting them, add a molex connector inline about halfway down those two wires, and put a second molex connector on the wires going to the two JAMMA pins (25 is P1, and the one on the other side is for P2 (Pin c))

It'll look like this:
Pheer the Mad ASCII Art Skillz!

That way, you can pkay MK again if you chose to. (although I couldn't imagine why, 'cause I can't stand MK personally)

definitely make an adapter! There's no reason to F'up the cab by cutting the kick harness.

thx for all your help guys :>

can't wait for Snk Vrs Capcom to arrive now so i can start kicking some ass hehe

-DeN-

Check your Jamma harness as well, mine already had the 4th button wires, they just werent attached to the actual buttons. A quick disconnect of the MK2 wires and plugging in the 4th button wires fixed it