The Nintendo Entertainment System (NES) is region locked using what is called the NES10 Lockout Chip. It prevents any out of region games from running by checking for the "Key" chip that is inside the cartridges and preventing any software from running that was deemed not usable for the system.
This guide will show you a number of ways to disable the 10NES Lockout Chip to make the console region free.
This is a non-destructive method that only uses two wires to disable the chip.
Confirmed working with:
Alternatively cutting pin 4 of the chip will prevent it from working. This is a quicker method but it permanently damages the chip.
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