JAMMA Power Wiring

kingdbag

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Quick question... it looks like my Open Ice and Hit the Ice use -5 volt on the JAMMA connector. My Golden Tee harness doesn't look to have -5 volt wired on it (5 and E are empty). What would happen if I plug in one of the boards in without the -5 volt? I just want to test them to make sure they power up and display correctly on my montior. I'm looking to not fry my board if it for sure needs the -5 connected as well. LOL

Anyone know if it's safe? I don't know crap about power so that's why I'm asking... =/
 
It's safe. The -5vdc is for the sound to function. Without it, you'll simply have no sound or really bad/loud static, depending on which game is plugged in. You'll be fine.
 
Sweet! One other newbie question... If you ever wire buttons, controllers or anything like that backwards. Does that have the potential to kill anything? Or the stuff would simply just not work until you wire it correctly? I'm sure power being wrong would be bad I'm just not sure about all the other stuff on the harness.
 
Sweet! One other newbie question... If you ever wire buttons, controllers or anything like that backwards. Does that have the potential to kill anything? Or the stuff would simply just not work until you wire it correctly? I'm sure power being wrong would be bad I'm just not sure about all the other stuff on the harness.

There's no real way to wire them backwards. As long as the input wire and ground wire are attached to the switch (it doesn't matter which wire is on which contact), it will still work.
 
Thanks for the help zeno... You were right about the sound. Hit the Ice wasn't too bad. I could actually hear the audio with some odd sounds here and there. My Open Ice board was totally pissed and was making a horrible squealing noise, but at least I could test the boards and make sure they booted up.
 
the first CVSD Williams Y-unit hardware sound boards needed -5 for the speech chip; without it you'll be missing half the sounds. this was changed on later sound boards from Terminator 2 and Total Carnage into the T-units, the Oki speech chip didn't need -5V. this becomes problematic if you have a bunch of these games and a lot of harnesses -- undoubtedly you can make the same mistake I once did and hook up a not -5V harness to one of the CVSD boards and get that half missing sound thing. :)

from T-unit onward on DCS games, -5 is needed for the DCS DSP. without it you get pretty much the theme song to the gateway to hell.

I'm surprised Hit the Ice needed it since it's a Taito game. they must have only provided the software, cause all the other Williams games of the era did need -5.
 
So now I know if I'm missing -5v the game will still work... what happens if you have -5v on your harness and you connect that harness to a board that doesn't use it?
 
So now I know if I'm missing -5v the game will still work... what happens if you have -5v on your harness and you connect that harness to a board that doesn't use it?

Nothing. If a board doesn't use it, the trace should be dead/open at the edge connector.
 
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