Things You'll Need
Instructions
Disassembly
Remove the expansion slot covers on the bottom of the Nintendo GameCube console.
Unscrew the four corners screws on the bottom of the GameCube using a screwdriver with a security bit. These screwdrivers are available at some online gaming specialty stores or import gaming stores.
Flip the GameCube so it stands right side up. Remove the top half of the console's plastic casing.
Remove the screw on the exposed lid switch with a small Philips-head screwdriver.
Remove the GameCube's front and back panels by unsnapping them. Be gentle with the front panel as it is attached to the ribbon cable that connects the GameCube's motherboard to its controller ports.
Remove the four screws on the controller port and the two screws in the small pillars on the GameCube's left-hand side (when facing it from the front).
Gently remove the console's fan, keeping it attached to its cables, and set it aside.
Unscrew all screws along the GameCube's DVD unit and remove the DVD unit to reveal the motherboard and heatsink.
With a small Philips-head screwdriver, unscrew all six screws securing the heatsink to the motherboard. Pull the heatsink off the motherboard very gently, taking care not to damage its solder joints.
Soldering
Identify the three resistors on the motherboard. They are in a row above the largest square component on the board. The middle resistor should be labeled "R6."
Strip the tips of the wires pieces on both ends to expose the metal inside.
Melt a small amount of solder onto the tips of the wires on both ends.
Solder one of the wires onto the left point of the R6 resistor.
Solder the other wire onto the right point of the R6 resistor.
Secure the wires with a very small dab of hot glue.
Place a small 2-or-3 pin switch (available at electronic parts stores) so that the switch comes out of the rear vent on the GameCube, close to the console's digital AV out.
Solder the wires to the switch.
Reassemble the GameCube console.
Flip the switch only when the console is turned off. One position should enable the console to play Japanese games while another position allows it to play American games.