Instructables

Step 16: Disabling the Lockout Chip

This is an optional step, you may skip it if you like.

What you need:
Soldering Iron
Small screwdriver
Piece of wire

The lockout chip in the NES was included to prevent pirated games from running in the console. It is also the reason that you get the blinking screen. If the console's lockout chip and the cartridge's lockout chip don't communicate, then the game won't play. Half the time, it's not because of dirty contacts. The games would run fine if it weren't for the lockout chips. Disabling it means a much higher success rate.

PULLING UP PIN 4
To disable the lockout chip on the NES, first locate the actual chip. It is close to where we soldered the video amp, and it is labeled 3193A.

You need to pull up pin 4 of the lockout chip. Taking the whole chip out won't work, because it is connected to the reset line, and the console won't run without it. Instead, find pin 4 of the chip. The first picture shows pin 4. Put the small screwdriver under the pin to kind of pull it out of the hole. At the same time, heat the lead from the other side of the board with your soldering iron. Pull the pin out so it's not connected to the board.

GROUNDING THE PIN
You could be done right there. The lockout chip is disabled right now, but it is still a good idea to connect the pin to ground. Take your piece of wire and solder one end to the pin you pulled up, and the other end to the silver grounding strip going all around the board.

All your games should now run very well. The NES board is now complete. Next we'll build the power supply for it and test it out!
 
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Jaako11 months ago
I tried to do this to my nes and the whole 4th pin popped out and my nes doesnt turn on anymore! Can you help please? Ps. Sorry for my bad english.
Did you know that 1 example of a NES pirate game is Somari? It is a Sonic game who Mario is the main character. It is released for the NES instead of the Genesis.
Wesley12 years ago
On my nes mother board nose not have "CIC" but the number 3193 and the copyright is 1985
redsoup3 years ago
If you have a clone skip this step
XCVG5 years ago
It's better to add a switch between +5v and ground, because some games don't run without the chip.
If I do this to my home console will it run better, or is that just a stupid idea?
1up (author)  adamdonovan885 years ago
No, it'd be fine. If you want, you can add a switch to turn it on and off.
should i do anything if pin 4 pulled out of the chip!? I just tested a game and it still works
1up (author)  ryaninspiron5 years ago
It's fine.