Disabling NES Lockout Chip
Before you take your Nintendo Entertainment System 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.
Once the lockout chip has been disabled, you will be able to play virtually any NES game from anywhere in the world on your NES, you will still need an adaptor for Famicom games though because of the physical differences.
Disabling the lockout chip in a NES is quite easy, simply take apart your console completely, remove the top, then the metal shielding, remove the motherboard from the case as you'll be working on the underside of it.
Look for a chip with 16 legs at location U10 (probably near the Power and RF sockets). On the UK console owned by mmmonkey the chip has 3197A written on it. Locate Leg number 4, with the writing the correct way up, count along from the left on the row of legs nearest you.
mmmonkey chose to simply cut the leg very near to the motherboard (after carefully bending the capacitors out of the way). Once the leg has been cut, lift it away from the motherboard.
You could leave it like this, or you could do the correct thing and solder a wire from the lifted leg to Ground. mmmonkey melted some solder onto legs 4 and 11 (legs 11, 12, 13, 14 and 15 are all linked to Ground), then simply attached a piece of small wire between the tinned legs.
That's it, you could reassemble most of you NES and test it before completely reassembling it. Another side affect of disabling the lockout chip is that the power light on your console will no longer blink if you switch on your console without having a game inserted.
This procedure is very well documented all over the web, mmmonkey first saw it on Mark K's website, and recommends that you visit it to read a more technical document on this procedure and other mods.
