20EZ EZ20 Squeal and LOUD hum - fixed!

texasmame

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Just for future reference here for someone hopefully. . .

Had a Nintendo monitor with amazingly loud hum and high pitch squeal. Touching/moving the volume pot seemed to change it, so swapped out pots. No change.

Then noticed that if I held the pot the noise would go away. Not a grounding issue - all checked out as grounded properly.

Looked at the traces on the audio board and followed out from the volume pot, replacing caps as I went. C374, which looked fine from above, was rotted out on the bottom. Replaced it and no more squeal and loud, loud buzz. :) Well, now just have the very low "normal" Nintendo speaker buzz, that is. :(
 
Electrolytic capacitors are a necessary evil. One of my favorite websites/forums is badcaps.net. It has helped me quickly repair a couple of LCD monitors and a graphics card by identifying the most common components that fail.

Maybe you can report that issue there.

Best,

Bill
 
Yeah, there are one or two specific ones that usually have a leg rotted off. Same goes for the neckboard cap and one other big cap on a GO7 chassis.
 
Electrolytic capacitors are a necessary evil. One of my favorite websites/forums is badcaps.net. It has helped me quickly repair a couple of LCD monitors and a graphics card by identifying the most common components that fail.

Maybe you can report that issue there.

Best,

Bill

Looks like a nice, thorough site but I don't see any section for classic games. . .
 
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