Cleaning GBC audio?

[Einzelherz]

I just bought a GBC, my first, and I've been messing around with it today. It's already had its capacitors replaced by the seller. I notice that even with the volume all the way down there is a lot of static and buzz coming from both the speaker (not loud, but that's understandable) and the headphones.

I tested the same games in a GB Pocket and an original GBA and GBA SP. The SP was very clean, and while the other two had some static still, it was very minimal, maybe 10% of the total max volume. This new GBC's static is closer to 35-40% of the total volume.

Is there really anything that can be done? I resoldered a few of the points in case there was some bad connections, but that didn't change anything. The static (on all the systems) seems to be connected to the screen's output, regardless of if it's connected. Strangely too, wiggling the power switch up and down creates a scratching noise.

I don't hope for much, but thanks in advance if anyone has any experience with this.

 

[sandytf]

Check for damaged or broken traces, especially ground traces. Static and noise can often be caused by bad ground connections.

 

[Einzelherz]

I gave it a once over and all of the board components looked quite good. Is the sound chip the small area with the button cell sized round black cylinder that's on its own separate board adjacent to the speaker? If so, I'll touch up those joints too.