G23 RF sound interference frustration

[sccarlso]

I do my searches first but haven’t found anything helpful.  Also I’ve not been able to find an AVP 3.0 G23v1 “service manual” with hardware hookup diagrams or hardware troubleshooting in posts or the files area.  Does anyone have a PDF?

My G23 works fine otherwise.  But once booted, my audio is off balance.  Video spin audio is quiet, but pays are much louder. And on cashout it’s like max volume. 

The main issue though is it has a constant buzzing rhythmic noise even when idle with no play.  It’s rhythmic, so after checking connections & cables.  Which were good.  I did some simple tests, and after unplugging the main fan to the right of the audio amp, about 70% of the audio noise stopped.  The remaining but lower rhythmic noise is likely coming from the PSU fan.

The amp was replaced yet the noise remained.  So just basic electronics, interference from the machine fans seem to be the cause.  Possible something not properly grounded?

I see the audio source on the brain box is connected to the middle jack.  I know one is mic, one speaker, and one is line out.  But not sure if it should be using speaker or line out to the amp…  The cable Y splits and each goes to a black box (looks like a filter, on each audio cable which I’d love to know what they are).  Then to the amp inputs.  One is R/L, the other is bass.

I even bypassed internal audio cabling with a new shielded stereo Y cable but the issue remains the same. 

Any experts have a suggestion for what might not be grounded, or improperly grounded?  Or some other issue that is causing RF interference from the fans into the amp to cause this audio noise.  It’s so noisy even when idle that I don’t even want to keep it on.  Ugh. 

Secondary issue, may be cut and dry.  I can’t connect my Tito@home card as it has a DCS daughterboard on the comm port instead of the RS232 card.  Is the DCS board still RS232?  So if I could find the exact pinouts I could tie into for the Tito?  Or is DCS a proprietary protocol and I’ll just need to put the RS232 model card in there for my Tito to use?  Not difficult, but thought it would be worth asking. 

That’s easy if so.   But the sound interference has me baffled without a diagram of wiring.  Would be great if I could add a simple resistor or another ground somewhere that would block that RF noise from the fans from reaching the audio signal!

All suggestions appreciated!  Already cleaned the audio jacks with that special cleaner as well mentioned in other posts with no joy.

Many thanks!!!

[sccarlso]

Sound Amp/Speaker assy replaced and no more issues!

Likely a ground issue, but not on the harness or cabinet.  In the amp itself.