I have been looking into doing the audio mod, but not sure about it yet. Apparently I managed to brake the GBP's board while removing the connectors and switches...

But another board is already in the mail. Let's see how I manage that one
Meanwhile, can someone tell me why my GBP (left) has this resistor (4.7k Ohms 5%) on it. And I found picture (right) of another GBP that had three of them connected like so. Is this related to the sound. Something that Nintendo wanted to patch in some models? As I see that there is no resistors in the picture shown in sound mod-tutorial.
