This is a follow-up to the Sega Genesis Model 1 region modification.
This allows you to switch from ENG <--> JP
-->You will need:
-->Philips head screwdriver
-->SPDT Switch (I think it's called that. It has three connection points on the bottom)
-->Drill with Drill-Bits
-->Thin gauge wire (Three different colors)
Please read ALL of the image notations, as they are of great importance.
Step 1: Time to Take Things Apart!
Unscrew everything and completely dismantle the Genesis!
Step 2: Find Your Working Area.
Make your soldering iron is on.
This part is very tough. I recommend that if you're not very goodworking with small electronics, STOP NOW!
Locate the small area we're going to be working with.
Step 3: Preparing the Work Area
If you happen to be myopic, then you should thank your handicap.
Here's where the really hard part comes.
Locate Pin 107, and lift it with something very small and sturdy.
Locating this shouldn't be too hard; there's a 105, and it's counting from there.
After that, you can put some tape under it.
Step 4: Soldering, Soldering, Soldering!
Now for the soldering!
Add solder to pin 107
Add some solder to the end of 108's route. If your Genesis doesn't have a nice convenient copper plate, you can scratch away to expose some of the copper.
Add some solder to the ground area.
Step 5: Preping the Wires.
You'll need the three small gauge wires now.
Strip one end of the wires.
Add solder to the stripped ends.
Step 6: Connecting the Wires
After this step, you're home free!
Just solder the wires to the pre-determined spots.
Step 7: This Is Optional.
The Sega that I was originally going to use for this instructable, broke. Pin 107 cracked off, so this step is for caution.
Again, this is completely optional. For aesthetics as well as caution.
Step 8: The Switch
So now that everything is set, you have uneven lengthened wire.
Make them even!
Strip and solder. Refer to Step 5.
With the switch, add solder to the three connection points. Go nuts.
THE WIRE FROM PIN 107 WILL GO IN THE MIDDLE!
Step 9: Placing the Switch
Depending on the type of board you have, the placement of the switch is completely up to you.
I happened to give it a circuit-bent look.
Step 10: Modifying the Cartridge Bay.
This is really easy.
This just makes it so that Japanese games may fit in the cartridge bay. That's all.
Step 11: Re-assemble
Re-assemble your Genesis.
Step 12: Testing the Results.
Most of the newer games have a region lock, so try a variety of games to test out your mod. You can now order the games you couldn't play before.
You can just switch back and forth between regions.
Have fun and leave feedback. :)