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Re: Questions about a Game Cabinet Intermittent Blue
Question from Timothy: First off, great site, and I hope you check for new e-mails before you reply, as this is a follow up to my original e-mail.
I have two current problems with my arcade system.
1. There is no Blue most of the time. None whatsover shows in the test menu.
However, while playing it the blue came back on suddenly, I thought this was due to my wife jumping up and down after beating me. The next day, it went back off while we were playing the game with no jumping involved.
I have done a continuity test on the wire running from the pcb blue output to the monitor chasis blue input. I got continuity from the pcb to the chasis, so I assume the wiring is fine.
I have checked the power at the pcb level by placing the black lead on the video ground and the red lead on the blue video. I get a result around 1.80. However, when I test the red pcb connector, I get something around .96. Is this normal or does this indicate a problem with the board?
I know a capacitor kit is often a resolution to many problems, does my issue sound like a cap kit would fix it?
2. There is no sound whatsoever. The speakers crackle when the cabinet first comes on but make no noise from then on.
I get a continuity sound when I follow the sound wiring. However, I get the the continuity beep regardless of which wire connector I touch the lead to at the speaker level. Is this normal or does this indicate a problem.
The manual for the game suggests “check for -5 volts on edge connector of pcb” and the same for +12 volts in the troubleshooting sound section. Where should one check for this? The Jamma diagram does not have a location for -5 volts. I checked the power coming into the pcb and the voltages were close to the proper amounts on the component side connections at least. I checked the voltage on the sp+ connector (which I assume is speaker) and got a little over 6 volts. If that is supposed to be -5 then it is way off. Also, there is no wire running from the -5 volts terminal on the power supply, which doesn’t suprise me as the manual only calls for +5 and 12 volts from the power supply.
Some general questions from my testing:
When I don’t have the Jamma harness attached to the pcb, I get 5.00 volts and 12.89ish volts at the power supply. When the Jamma harness is attached, I get 5.00 volts and 12.02 volts at the power supply. Does this indicate an issue with the power supply or is this normal?
I see you have a login for donors, but I can’t find a link to donate. Where is the donation link on your site?
1 answer
Response from Tim: 1. It sounds more to me like a bad solder joint on the back of your chassis. If you flip it over and resolder the back of the pins where your connector comes in that could fix it. I have seen this several times with the symptoms you describe. A cap kit probably will not help this. You should not have voltage going there so the fact you get 1.80 and .96 is ok in my opinion.
2. Your -5 comes from pin 5 of your jamma connector (or pin E if you are on the solder side) which is between your +5 and your +12. You could run a wire from your power supply and touch the contact under your -5 thus giving it -5 and see if that helps your sound, but I dont remember SF2 using the -5 it shouldn’t hurt though.
General question: No very normal and ok. Its what we would call “being under a load”
That’s very nice of you to want to contribute. I will forward this to Jonathan and he will let you know how to contribute if you want. I know we were asking for donations for a HD camera and when we raised the money we took it down. Good luck with your game. Please keep us informed of your progress. Also, does your sound go through a volume pot?
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