SNES 50/60Hz Switch and Disable Lockout Switch

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 probably 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 I have 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 I mod a console it usually get a good clean as well.  Then decide where you’re going to mount the 2 switches, I prefer 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 (here’s some help with that).

Nicely filed holes for switches

Mounting the switches in place makes soldering the wires easier.  Next solder the 2.2K resistor into place as per the following photo, I do 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 I use double pole switches, the resistor is soldered to 2 contacts of each switch, this is just to make life easier later on.

Switches and resistor in place

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.  I prefer 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.

The voltage regulator

5v and Ground wire soldered into place

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.

5v wire in place

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.

Ground wires twisted together and tinned (badly!)

Powered switches

Now you’ve got your switches fully prepared, it’s time to start on the chips on the motherboard.  First we’ll do the lockout chip, located in the bottom left of the board (probably, it varies as there are a couple of board revisions), it’s got 18 legs, it could have the code F431A or F411 printed on it.

We need to separate leg 4 of this chip from the motherboard.  I usually do this by heating the leg with the soldering iron, then gently teasing it away with either a pin or a very fine blade.  Once the leg has been separated, isolate it by placing some electrical insulation tape under it.  If you’re nervous about doing this then find something broken to practice on, you don’t want to break your SNES, and there are some more difficult legs to lift later.

Leg 4 lifted and isolated

Soldering wire to chip legs is made much easier if you use Kynar, cut a piece to fit from the switch to the chip, thinking about which route to take so the shielding doesn’t interfere with the wire.  The wire should be soldered to the middle leg of the switch which is linked directly to 5v and Ground, finally – carefully solder the wire to the lifted leg.  You can also see how much thinner the Kynar wire is compared to the 5v and GND wires used.

Lockout switch fully soldered

Finished leg

You could take the opportunity to test your console now if you wanted, but be very careful not to damage anything while the console is disassembled.  And remember to discharge the console after testing!

Next it’s onto the 50/60Hz switch, a bit more difficult this one – there’s two chips to lift legs from, and they are smaller than the lockout chip.  You’ll need to locate the PPU chips.  From PPU1 you need to lift leg 24 (count very carefully back from leg 30 which is marked).  For PPU2 lift leg 30, this is easy as it’s the end leg.  I used a soldering iron and blade method the same as before.

PPU1 with leg 24 lifted

PPU2 with leg 30 lifted

Again, place some insulation tape under the legs to isolate them.  Now you need to solder wires from the switch to both the legs, you could solder the wire from switch, to PPU2, then from PPU2 to PPU1.  I don’t like doing this as it may put unnecessary strain on leg 30 of PPU2, so instead I solder 2 wires to the middle contact of the remaining switch.

Isolated legs of PPU chips

Wires for PPU chips

Getting near the end now, cut the two PPU wires to length – again think about the routing of the wires and the shielding.  Carefully solder the wires in place.

PPU1 wire

PPU2 wire

It’s a pretty good idea to cover the exposed legs of all three chips with insulation tape.  This will help secure the delicate legs, as well as insulating them of course.

Insulated legs and wire route

Congratulations – you’ve finished the soldering, now you’ve just got to test/re-assemble your console etc.

Here’s an idea of where I like to place the switches, and how to label them (done using a Dymo LetraTag).

Labelled switches

Switch positioning

Now you’ve finished, you can enjoy most SNES games in 60Hz full screen, full speed.  Like Super Mario World here.

SMW at 50Hz

SMW at 60Hz

There are however some games which have graphical glitches, so these will need to played with their intended setting (this is one reason we fit a switch instead of permanently modding).  SuperFX games seem to have problems, look at the missing graphics under the word Start in the second picture below.  Check this out for a pretty good list of these glitches.

Running at 50Hz

60hz with glitch

Another reason for fitting a switch is because some games check for 50 or 60 Hz when you start up your SNES, if they don’t find what they expect then you’ll receive an error message similar to the following.  You can of course start the console up in the expected mode, then switch the desired mode.

Wrong setting

There are even a few games that will refuse to load with the lockout chip disabled, a PAL copy of Kirby’s Fun Pack refused to load on my PAL SNES unless the chip is enabled.  So simply disabling the chip is not a good idea.  Another game that refuses to load is Super Mario RPG, so for maximum compatibility it may be best to have both a PAL console as well as an NTSC console (an American might be good for its wide cart slot).  It seems you can modify your Super Mario RPG cart to try and get it to work on your switched console.  Alternatively, the SuperCIC mod is fully compatible with all games.

Depending on  your exact console model, the layout of the board might be different to the photographs in this guide.  AND… there are some later motherboard revisions that can’t be modified with this standard 50/60Hz switch, the PPU chips are combined – usually called a 1 chip ppu, here’s a good guide to find out if a console is a 1 chip model withough opening it up.  This is also the case with the smaller “Jnr” models of the SNES/Super Famicom.  Check this out on how to fit a switch to one of these consoles.

Credit must go to Mark K, I first saw the information for this on his very interesting website.  Make sure you visit to read more technical information about this and other mods.

Of course, you can fit the switches anywhere you want, and toggle style switches etc.  Here’s another idea for where  you could mount the switches – this is after removing the RF unit as I wasn’t going to use it anyway!


Summary of Components

  • 2 x Single Pole – Double Throw switches
  • 1 x 2.2K ohm Resistor
  • Wire (Kynar is easiest for the chip legs)