SNES SFC 50/60Hz Switch with Lockout Switch (continued)
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, 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. mmmonkey usually does 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.
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.
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. mmmonkey uses the soldering iron and blade method the same as before.
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. mmmonkey doesn't like doing this as it may put unnecessary strain on leg 30 of PPU2, so instead mmmonkey solders 2 wires to the middle contact of the remaining switch.
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.
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. You can also see the route that mmmonkey used for the wires.
Congratulations - you've finished the soldering, now you've just got to test/re-assemble your console etc.
