Help Swapping Jamma PCB's

N1kolai

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Hi Guys,

I've got a Double Dragon conversion cab, and I'm trying to do my first PCB swap to Crime Fighters. When I got inside to do the swtich I noticed that the DD pcb not only has a Jamma connector, but 2 ribbon type connectors on the bottom too. My new PCB I'm trying to install doesnt have the black ribbon connectors on it and I was wondering if I need to buy some for it, or am I supposed to somehow remove the ones from the DD board and use those?? HELP!..

Also, when I hooked back the 2 ribbon connections to the DD board I don't think I was able to get one of them seated properly, so now the display seems messed up. (At least Im hoping thats what it is and I didnt knock something loose while moving the cab.)

All in all it was a bad night for me as an arcade noob :(

Can anyone please tell me what I need to do, and what those 2 ribbon connections are?

Thanks a million!
 
Some game boards are two-board stacks (or more than two), linked together with ribbon cables. Other boards are standalone, single boards. Unplug the Jamma harness from the Double Dragon boardset, remove the whole thing, and replace it with the new board. NEVER try to mix and match individual boards from different games unless they were specifically meant to be mixed (CPS2 games, etc).

-Ian
 
Some game boards are two-board stacks (or more than two), linked together with ribbon cables. Other boards are standalone, single boards. Unplug the Jamma harness from the Double Dragon boardset, remove the whole thing, and replace it with the new board. NEVER try to mix and match individual boards from different games unless they were specifically meant to be mixed (CPS2 games, etc).

-Ian

Ah okay..It looks like the new PCB had a place for a couple of those black ribbon connectors, so I assumed it needed to be installed using them. I'll just remove the whole stack and put in the new one then. Is it possible that not getting one of those ribbons seated properly has cause my display to do weird things?

Thanks!
 
Ah okay..It looks like the new PCB had a place for a couple of those black ribbon connectors, so I assumed it needed to be installed using them.
Some game boards have what looks like expansion connectors, or empty sockets - that's because many times the same basic printed board was used on multiple games. So, there might be another game that uses that same printed board artwork, but with those connectors populated and a daughter board connected there, or more ROM chips installed.

I'll just remove the whole stack and put in the new one then. Is it possible that not getting one of those ribbons seated properly has cause my display to do weird things?
Definitely. Go back and double check them, make sure you haven't bent any pins, and that they're seated correctly. Those cables invariably have address and data lines in them, etc. The only reason the interconnect cables are there is because in many cases the game required too much board space to fit on one circuit board. There's a practical limit to how big a board can be before you start to have problems with power distribution, or the board sagging under it's own weight. Also, producing a single large board would be vastly more expensive than multiple smaller boards. So, they split the game logic/ROMs/etc onto two or more boards, and link them together somehow. Either with ribbon cables, or connectors that allow the boards to plug on top of one another, or even a backplane. Some games are one or two boards, but there exist games that consist of three, four, or more boards. Unless the game was designed to have an interchangeable ROM section (CPS2, Neo Geo, etc), the whole game boardset stays together, as it's interconnects will be incompatible with everything else, they're just meant to bridge signals between boards.

-Ian
 
Awesome! Thanks a million Ian! I feel better about the whole situation now! :)
 
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