Naomi NOOB questions: sound with capcom i/o; ground plug

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OldFoo

Naomi NOOB questions: sound with capcom i/o; ground plug

Post by OldFoo »

Hello all.



I recently purchased a full cabinet setup of a NAOMI(1), MVC2, and Capcom I/O inside of a Taito Egret II. I noticed a few issues with it so I wanted to check with you guys to see if there were any suggestions.



First, the three-prong plug is missing its ground. Well...more like the ground is there halfway, but snapped off. I was told this was unsafe by a friend who works with pinball machines; I'm not sure as the cabinet powers up with no issues or stray electricity.



Second, I'm having sound issues. Upon start-up, the cabinet's sound is incredibly loud, no matter how low the volume is set on the Capcom I/O. After about 5 minutes, it becomes much, much softer. There appears to be some static sound upon start-up but that disappears once the game is loaded.



In the test menu, the right speaker works in the sound test, but the left speaker does not. However, in the game settings; changing to mono gets sound in both speakers (albeit either really loud or really soft as talked about above).



I checked the connections and everything seems OK, but I haven't managed to check the sound output directly from NAOMI...i.e. plug in a different set of speakers into the RCA jacks; that's my next step. If that works as expected, I can whittle the problem down to either the JAMMA connection or the I/O itself... if you guys have any other thoughts I'd love to hear them...here are some pics.



Ground prong missing.



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Left speaker connection.



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JAMMA harness.



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Power supply.



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RCA hookup



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Full setup.



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OldFoo

Post by OldFoo »

A ground prong on a plug doesn't affect normal operation, but it is there in case something goes wrong. In case of electrical short, the power should flow to the ground, instead of, say, your body. In a commercial setting (an arcade or business), it may even be illegal in some countries to have ground removed from something that's designed to have one. Probably not a crime in a home setting, but do yourself a favor and replace that plug.



Can't help much on the sound issues, as you're already doing what I would do.
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