I finally got my Game Boy Color speaker to stop buzzing after 11 tries and a q-tip
Picked up a beat up teal Game Boy Color at a flea market in Portland for 8 bucks, and the speaker had this nasty buzz on every sound effect that drove me nuts. I tried new batteries, cleaning the headphone jack, even a dab of solder on the speaker contacts, but it took 11 separate tries over 3 weeks before I realized the shell screw near the speaker was over tightened and pinching the pad. Has anyone else chased a noise for weeks only to find it was just one screw the entire time?
Honestly the screw thing sounds like a lucky guess more than a real fix. Eleven tries over three weeks means you basically poked at everything until the buzz quit, and the screw is just the last thing you touched before it went quiet. That's not diagnosing a problem, that's superstition with a screwdriver. If it were really the pad getting pinched, a fresh set of batteries and cleaning the jack would not have changed anything at all, and you said they did. A loose or tight screw does not come and go like a buzz that tracks every sound effect. More likely the speaker itself is just old and tired, and you'll hear that buzz again in a month.