Capcom Q25 Q-Sound Amplifier Problem

Kid Dynamite

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I just moved to another location and moved the cabinet with me. I tested it prior to wrapping it for transport and everything was fine. After plugging it in at the new location, the Q-Sound amplifier doesn't output to the speakers. I switched in another working Q-Sound amp and the same problem persists. The amplifier powers on and I cannot find a loose or broken connection anywhere yet I don't even hear the amplifier power on through the speakers when the cabinet turns on. The rest of the cabinet functions perfectly and jamma audio has no problems. I've also tried different pcb's with RCA outputs and they all end up with the same problem. The cabinet didn't receive any horrible shock during transport. Any ideas?
 
Try checking the continuity of the speaker wires. You may have had a break in the wires or at the speaker connection. Or there may be a bad connector from the board to the speaker.

If you can do it, connect a known working audio device (stereo, AM/FM radio, walkman, MP3 player, etc.) to the speakers to test them out.

ken
 
Try checking the continuity of the speaker wires. You may have had a break in the wires or at the speaker connection. Or there may be a bad connector from the board to the speaker.

If you can do it, connect a known working audio device (stereo, AM/FM radio, walkman, MP3 player, etc.) to the speakers to test them out.

ken

Thanks for the input, Ken. The Q25 is like many other candy cabs in that the 4-pin speaker harness plugs into either a mono harness that runs to the JAMMA harness or a stereo harness that runs to the Q-Sound amp. The speaker harness and speakers are fine since the JAMMA audio is flawless. I can't find a break in connection between the amp and speaker harness anywhere and I don't have the harness type to test the amp with another system. I think I'm just going to carefully run some wires from the speaker out on the amp to some left-over full range speakers that I have to see if I can narrow down the possibilities.
 
I tested the amp again running wires directly from the output to the speakers and still no sound. The light on the amplifier is turning on so it's getting power and I'm positive that at least one of the two tested amplifiers works yet there's still no sound. Can a voltage deficiency cause a complete cut-off of sound? Everything else in the cab works fine so I'm not sure how a voltage defiency to the amp would be possible.
 
I'll throw my hat in the ring on this one.

So let me see if I understand so far. You get Mono sound out of the JAMMA Edge connector from the board in question without issue, but you get no sound out the board from the L/R RCA Jacks on the CPS board?

I'd get a 3.5mm Male to 2x RCA Female connector like this: http://www.radioshack.com/product/index.jsp?productId=2103710

Hook that up to your Q-Sound amp's input cables, and plug it into your MP3 player, phone, etc, and see if you get sound.

If you get sound, looks like you've got a problem with Stereo/Mono Mux on the board you're plugging in.
 
Thanks for the input. I've been meaning to hook up a different device to it to see if any good comes out, but none of my CPS2 a-boards are outputting sound through the amp so I imagine that other devices wouldn't work either. Been kinda busy with a heavy volume at work and moving in to my new residence. I'll let you know what comes out of it.
 
just a silly question... are your games set to Mono or Stereo in the test menu?

I think if it's on Mono it only plays out the JAMMA harness, turns the RCA jacks off.
 
just a silly question... are your games set to Mono or Stereo in the test menu?

I think if it's on Mono it only plays out the JAMMA harness, turns the RCA jacks off.

They're set for Q-Sound in the options. Every game I have with RCA outputs doesn't come out at all when the Q-Sound harness is connected.
 
Yeah, going to have to test the function of the amps with another device first. The RCA jack outs are extremely low voltage (~0.7v peak to peak). You won't be able to hear anything on those jacks without using something like a Crystal earpeice.
 
well, CPS2 boards have been known to get weird with the volume settings too. I don't entirely remember how to correct this exactly, I had an A-board where the audio would completely fade out, and I think I had to turn the volume all the way down or all the way up (at the little volume buttons).

I don't entirely understand how this could have happened just by moving the game though. strange.
 
I think to reset the volume on the A board you hold the volume down button when you power it on. I may be wrong as this is from memory, but it's something like that. I'm presuming this isn't the problem as he's used different boards with RCA output and verified his amp by using a known good one. Weird problem indeed.

Question. How do you know the sound works from the JAMMA connector? Did you test that in this cabinet? I was under the impression that the speakers would connect to the Q-Sound amp or the JAMMA connector, not both. Did you move the speaker connections, or did you put the board in another cabinet to verify the JAMMA sound worked?
 
have you ever heard of the term "field maintenance"?
clarification just in case:
My father is an electronics tech that was educated by the military. They have a term called "field maintenance" which is simply just banging on the side of the cabinet or housing. Sometimes this works, but not very often. I have done this in the past to TV's and am/fm radios to get the sound and or picture to work properly.
With older ham radios, simply just turning the volume control pot back and fourth several times works once in awhile.
 
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I think to reset the volume on the A board you hold the volume down button when you power it on.

That's correct. You hold it down until the game splash screen shows on the monitor. Then you can turn up the volume.

Step back and lolk at this logically.

Get a set of RCA cables that are 12' long... run them from the CPS2 game board to an audio input on your TV or home stereo system and see if you are getting sound. That will show you if things are working right from the game board.

After that check continuity between the RCA plugs that go to the board and the inputs on the amp... If all those check good (and not open or shorted from center to shield) and you know the speakers are good by plugging into the mono jack on the cab.... then the problem is in the amp, power to the amp, or that output cable that goes from the amp to where the speakers plug in.

RJ
 
That's correct. You hold it down until the game splash screen shows on the monitor. Then you can turn up the volume.

Step back and lolk at this logically.

Get a set of RCA cables that are 12' long... run them from the CPS2 game board to an audio input on your TV or home stereo system and see if you are getting sound. That will show you if things are working right from the game board.

After that check continuity between the RCA plugs that go to the board and the inputs on the amp... If all those check good (and not open or shorted from center to shield) and you know the speakers are good by plugging into the mono jack on the cab.... then the problem is in the amp, power to the amp, or that output cable that goes from the amp to where the speakers plug in.

RJ

I've tried 3 different A-boards and 2 different RCA cables already with no success and I've run the amp output directly to some full-range speakers without any sound. I've yet to try other input sources and other amplifiers to confirm the hunch that I have, but it seems really improbable that the cables and audio sources are the problem since all of them were working a week or so ago.
 
have you ever heard of the term "field maintenance"?
clarification just in case:
My father is an electronics tech that was educated by the military. They have a term called "field maintenance" which is simply just banging on the side of the cabinet or housing. Sometimes this works, but not very often. I have done this in the past to TV's and am/fm radios to get the sound and or picture to work properly.
With older ham radios, simply just turning the volume control pot back and fourth several times works once in awhile.

I've switched out the amplifiers entirely so I don't know that an impact jolt will set either of them straight. I guess I could try though.
 
I think to reset the volume on the A board you hold the volume down button when you power it on. I may be wrong as this is from memory, but it's something like that. I'm presuming this isn't the problem as he's used different boards with RCA output and verified his amp by using a known good one. Weird problem indeed.

Question. How do you know the sound works from the JAMMA connector? Did you test that in this cabinet? I was under the impression that the speakers would connect to the Q-Sound amp or the JAMMA connector, not both. Did you move the speaker connections, or did you put the board in another cabinet to verify the JAMMA sound worked?

The speaker harness on the cab connects to a mono harness or a Q-Sound harness. The Q-Sound harness runs to the amplifier output and the mono harness runs to the JAMMA audio output on the JAMMA edge connector. Mono works fine, no sound at all from the Q-Sound amp though. You can't even hear the amp power on when the cabinet is turned on, but the light on the amplifier turns on when the cab turns on. ?????
 
You had mentioned you enabled the Q-Sound option in the setup. I thought this was only to display the Q-Sound logo and chime in attract mode. You did go into output and verify it's set to stereo? I think it's set to stereo by default. Have you reset factory defaults and tried it?
 
You had mentioned you enabled the Q-Sound option in the setup. I thought this was only to display the Q-Sound logo and chime in attract mode. You did go into output and verify it's set to stereo? I think it's set to stereo by default. Have you reset factory defaults and tried it?

All board settings are the same as they were before. Again, I've used multiple A-boards since moving it and all are yielding no output when the stereo harness is connected to the speaker harness. Stereo settings just change the output to a stereo signal instead of mono, the Q-sound jingle happens either way. The RCA outputs still work if set to mono under normal circumstances, they just come out in mono. My cabinet plays no audio at all when the amplifier output harness is connected to the speaker harness.

There is no problem with the A-boards or settings or all the other RCA pcb's I've used in the cabinet.
 
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FIXED!!!!! Thanks to my boy willkaotix, this cab is running in glorious Q-Sound again. The ????? factor was due to a power deficiency at my last residence. Since the cabinet is Japanese the amp by default is wired to the 100v line on the transformer. This line reduces the voltage down to approximately 17% of it's initial input, 17v. Apparently the voltage at my last residence was low enough to be reduced to a compatible voltage close to the 17v mark.

So when I moved to my apartment back in June, I moved to a place that apparently has hotter voltage than my last residence. The voltage on the amp was 19.4V here at my new place using the default 100V line on the transformer. This makes sense as it is 95% accurate of 17% of 120V. So my buddy switched the line to the 120V transformer input line and the voltage dropped to 16.2V, well within the threshold of the amplifier which ideally runs at 17V. This never occurred to me before since the amplifier ran just fine at my last residence in the US.

So the lesson from this is that the Capcom Q-Sound amplifier shuts off if the voltage exceeds its threshold.

Another problem solved by my friend willkaotix. Thanks, buddy.
 
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