Audio buzz on NEO-GEO CD "Top-Loader" CD-T01

Ace_of_DiscaL

Timid Neo Newbie
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Dec 16, 2022
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8
Both through the A/V 8-Pin DIN and the Left (white) & Right (red) RCA outputs.

The buzzing fluctuates with the change in graphics displayed on screen, and is most noticeable during all black screens or all white screens.

I am now using a JGO power adapter replacement which I bought to comoare with the original POWCD-J brick. But the results are exactly the same.

I also have a pack of replacement capacitors on the way, so if someone knows which ones to swap out, I'd be very grateful, instead of having to replace all of them.
 

Neo Alec

King of Spammers
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Yeah, I think a recap is the right plan. I'd start with the video and audio circuits around the video encoder, audio DAC and output jacks.
 

wyo

King of Typists
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I had one with this problem. Let us know if you find a fix. Good luck!
 

maki

Kula's Candy
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Jan 1, 2022
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297
Swap all the caps, most of them are on the audio/video DaughterPCB, just a few for the main PCB.
Bad caps on the NGCD will produce lot of noise when the CD drive is running.
 

GohanX

Horrible Goose
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Before you start performing surgery, unplug the RGB cable and see if the buzzing on the rca jacks are still there while using composite or svideo. A shitty rgb cable can cause a ground loop that results in buzzing.
 

Burning Fight!!

NIS America fan & Rent Free tenant
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Before you start performing surgery, unplug the RGB cable and see if the buzzing on the rca jacks are still there while using composite or svideo. A shitty rgb cable can cause a ground loop that results in buzzing.
yeah, buzzing on pure white screens is a classic cheapo cable symptom.
 

wyo

King of Typists
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May 22, 2013
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Before you start performing surgery, unplug the RGB cable and see if the buzzing on the rca jacks are still there while using composite or svideo. A shitty rgb cable can cause a ground loop that results in buzzing.
Good advice and worth checking out. On my system at least it was definitely something internal. The same AV cables and PSU on a different system worked fine.
 
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