Disable 10NES chip on your NES toaster

Ever been infuriated by a game that appears to be starting correctly but the NES still does that annoying blinking power light and flashing screen ?   Thats the handy work of the 10NES chip installed by Nintendo on the front loader (toaster) models of the NES.

The purpose of the 10NES was to prevent pirate or unauthorized games from playing on the system by checking to see if the a chip on the cartridge matches up to the 10NES chip on the NES mainboard , but a slightly dirty or misaligned cartridge can trigger the 10NES chip into getting a bad reading and constantly resetting the console.  In retrospect this attempt at controlling the software that could be published to the console by using the 10NES seems to have been an exercise in futility as Tengen and other unauthorized publishers were able to reverse engineer the chip and come up with their own solutions that allowed the games published by them to be playable on the system.

 So, at this point if you decided that the 10NES is more trouble than its worth, lets get that thing disabled.

First thing you will need is a NES of course, and a phillips screwdriver.  I like to place my console on a clean towel to give myself a soft place to work and help keep screws and parts from rolling away.

Flip the system over and remove the six screws from the bottom of the case -

Once those are removed turn the unit back over and gently lift the topcover off.

Underneath the topcover you will find the RF shielding metal cover.  There are 7 screws around the perimeter that you will need to remove.

Once those have been removed carefully lift the RF shield off the unit.  It can sometimes catch on the projection on the ride side where the power supply unit is, and may take a bit of wiggling to come loose.

Now there are 4 screws that need to be removed from the cartridge tray (in red below) and two screws on either side of the power supply (left side of RF jack and below the RCA jacks on the right).

Now carefully lift the mainboard off the bottom case and turn it over, making sure none of the power button or controller port wires get caught on any of the plastic mounting posts.  There are 3 connectors that will need to be carefully removed, make note of which controller port wire connects to which port to prevent confusion later (the first controller wire is the shorter one and connects to the port that points directly at the controller port at the front).

Once the connectors are removed take the mainboad off the case and set it on your workspace.  The bottom RF shield should lift right off.

Now your looking at the bottom of the mainboard and you will need to locate the 10NES chip (in red).

We will be cutting the pin highlighted in Red to disable the chip.  I used a very sharp exacto knife to gently saw through the pin (its quite soft).  Be very careful to only cut the one pin and not to damage any of the capacitors near the 10NES chip.

Its not necessary to remove the pin entirely, just to break contact.  once you've cut through it completely, bending the unconnected lower piece away should be sufficient.

Now just reassemble in the reverse of how everything came apart and test out your now unblinking NES !