SNES SFC 50/60Hz Switch with Lockout Switch
There is now an improved Switchless Modification you can perform now.
Before you take your Super Nintendo to pieces, you should ALWAYS switch it on after you have unplugged it from the wall. You'll notice that the power light flashes for a split second, this is the console discharging, some people say you need to leave the On/Off switch in the On position for quite a while before dismantling it - this is up to you.
If you have started soldering in your SNES without discharging it, chances are you won't be able to switch your SNES back on again, it'll be dead! You've probably blown the internal fuse, which is easy to replace following this guide.
Here's a brief explanation of the mod - the lockout chip is disabled if leg 4 is grounded, it's enabled if it's receiving +5v. The machine will operate in 50hz mode if the PPUs (PPU1 leg 24, PPU2 leg 30 receive +5v, and 60hz if they are grounded.)
The Super Nintendo Entertainment System is quite easy to modify for 60Hz, it's even easier to disable the lockout chip so that the majority of import games will work. It is wise however to fit switches to enable these features to maintain maximum compatibility. So you'll need 2 Single Pole - Double Throw switches, a single 2.2K Ohm resistor and some pieces of wire (Kynar wire is highly recommended). You will need to follow the instructions as per the diagram on Mark K's website, just in case his site disappears, here's a mirror of the diagram. As usual mmmonkey has chosen small sliding switches, and can only get hold of double pole switches (that's with 2 rows of contacts to solder onto, only solder onto one of the rows).
You'll need to get into your SNES using a Gamebit screwdriver, whenever mmmonkey mods a console it usually get a good clean as well. Then decide where you're going to mount the 2 switches, mmmonkey prefers them on the left side of the console, hidden slightly underneath the console so that they don't spoil the looks of the console, but they're still easy to use. Once you've decided, drill/file the the necessary holes for the switches (see the Mega Drive guide for more info).
Mounting the switches in place makes soldering the wires easier. Next solder the 2.2K resistor into place as per the following photo, mmmonkey does it this way to keep it nice and tidy, the switch near the top of the photo will be connected to 5v (used for the lockout chip), whilst the resistor carries the voltage to the other switch (used for the 50/60hz selection). Because mmmonkey uses double pole switches, the resistor is soldered to 2 contacts of each switch, this is just to make life easier later on.
Now we need to get 5v and Ground to the first switch. These are taken from the Voltage Regulator near the rear of the console on the left. mmmonkey prefers to solder onto the bottom of the motherboard, luckily the pins are clearly marked - O for 5v, and G for Ground, cut the wire long enough to reach your first switch with a little spare (mmmonkey has used coloured wire to make it easier to follow the guide).
Place the motherboard back into the case, and solder the 5v wire to the first switch, it should be soldered to the connector which has the resistor already attached.
Now cut the Ground wire to length, but before soldering it to the switch cut another piece of wire to use to link Ground to the second switch. Twist the wires together and solder them to the first switch. Then solder the second Ground wire to the contact at the other end of the second switch.
