Nintendo Famicom AV-mod guide

Connecting an original Nintendo Famicom to a television in the West can be problematic, especially in the modern times. An AV-mod could solve this problem for you and as a bonus the AV-output will give you a lot better image and sound quality than the original RF-output. In this guide I will teach you how to perform an AV-mod on a Famicom (version HVC-CPU-07). If you don't know which version you own, I will help you find out in part A of this guide.

My modding method is an adaptation of the method used by Famicomania and I'd like to give credit where credit is due. My method requires no drilling or any other irreversible changes to the Famicom and all chosen soldering points are low risk. That being said, Famicoms are fragile, so follow this guide at your own risk. Now with the introduction out of the way, let's get started!

Required parts
2x Female RCA-plug (preferably 1 yellow and 1 white);
4x Wire (preferably in 3 different colors);
1x Transistor 2SC1815;
2x Resistor 22 kΩ;
1x Electrolytic capacitor 0,47 μF 50 V.


Part A - Disassembly

Step 1 - Case
Open the case by removing 6 screws on the bottom of the console.



Step 2 - Motherboard
Free the motherboard by removing 4 screws.



Step 3 - RF-module
Free the RF-module by removing 4 screws.



Step 4 - Controller cables
Disconnect the controller cables from the motherboard. You can put your nails or a screwdriver in the little gaps on the side and pull. These connectors can be tough and some force may be needed, but be gentle, as you don't want to damage the solder joints on the motherboard.



Step 5 - Power switch
Push the game ejector out of the way with your thumb and free the power switch by removing 2 screws with your other hand.

Step 6 - Check your version
At this point you should be able to take the motherboard and the RF-module out of the case. Now look at the white text on the top of your motherboard. If it says exactly "HVC-CPU-07", then your Famicom is compatible and you can proceed with this guide. If it says something else, then your Famicom is probably incompatible and you should look for another guide.




Part B - Soldering on the motherboard

Step 1 - Preparing the video joints
Add some flux and solder to the GND, VCC and VIDEO joint. These joints are located on the bottom of the motherboard.



Step 2 - Capacitor
Cut the negative leg of the capacitor to the appropriate size and carefully bend it in the right position. Then solder it onto the VIDEO joint. The negative leg of the capacitor is the shorter leg.



Step 3 - Right leg of the transistor
Carefully bend the positive leg of the capacitor and the legs of the transistor to the appropriate positions. Then solder the positive leg of the capacitor onto the right leg of the transistor. The text of the transistor should be facing you.



Step 4 - Center leg of the transistor
Solder the center leg of the transistor onto the VCC joint.



Step 5 - Resistor I
Cut the center and the right leg of the transistor and both legs of a resistor to the appropriate size. Then carefully bend the legs of the resistor in the right position and solder it between the right and the center leg of the transistor.



Step 6 - Resistor II
Cut the left leg of the transistor and both legs of the other resistor to the appropriate size. Then bend the legs of the resistor in the right position and solder it between the left leg of the transistor and the GND joint.

Step 7 - Video wire
Cut a long piece of white wire (or another color) and solder it onto the left leg of the transistor. This will be our video wire.



Step 8 - Ground wire
Cut a long piece of black wire (or another color) and solder it onto the GND joint. This will be our ground wire.



Step 9 - Preparing the audio joint
Add some flux and solder to the circled joint. This joint is located on the bottom of the motherboard near the ribbon cable that leads to the RF-module.



Step 10 - Audio wire
Cut a long piece of red wire (or another color) and solder it onto the above joint. This will be our audio wire.



Step 11 - Check your work
Check whether all the connections have been soldered as they should. Also check if none of your soldering connections are making false contact with any motherboard joints they shouldn't be making contact with.




Part C - Reassembly

Step 1 - Clean up
Clean up all the flux around your solder joints. I use 96% pure alcohol ketonatus for this. Don't forget to clean up around the audio joint as well.



Step 2 - Direct the wires
Direct the 3 wires to the outside through the hole above the channel switch. The channel switch is located on the RF-module. Don't put too much stress on the wires, as you don't want to damage your soldering work.



Step 3 - Secure the wires
Put a glue blob with a glue gun on the wires near the hole above the channel switch. This will protect the soldering connections on the inside from outside stress.

Step 4 - Reassemble the console
Put the Famicom back together. Follow the steps 1-5 from part A in reverse.


Part D - Soldering the RCA-plugs

Step 1 - Shells
Open the RCA-plugs and separate the shells from the tips. Push the yellow shell over the white and the black wire and the white shell over the red wire.



Step 2 - Video plug center
Solder the white wire onto the center of the yellow RCA-tip.



Step 3 - Ground bridge
Cut an extra piece of black wire. We will use this wire to bridge the ground from the video plug to the audio plug.



Step 4 - Video plug ring
Push the bridge wire through the yellow shell. Then solder both the ground wire and the bridge wire onto the ring of the yellow RCA-tip. Thereafter you can secure the wires by squeezing the metal brace and close the yellow plug.



Step 5 - Audio plug center
Solder the red wire onto the center of the white RCA-tip.



Step 6 - Audio plug ring
Push the bridge wire through the white shell. Then solder the bridge wire onto the ring of the white RCA-tip. Thereafter you can secure the wires by squeezing the metal brace and close the white plug.




Part E - End results

Congratulations! You should be ready now to enjoy your new AV-output.