NESRGB installation guide for front loading NES

This guide is for NESRGB version 5. Here is the old guide for versions 1, 2, 3. Some additional info is required for version 4.

  1. Basic ESD-safe practices
  2. Tools and materials required
  3. Open the NES console and take out the motherboard
  4. Remove PPU and mount it on the NESRGB board
  5. Wire to motherboard
  6. Wire and mount the AV connector
  7. Test and set up OVIN
  8. Reassemble the NES console

1. Basic ESD-safe practices

The NESRGB board and NES console contains integrated circuits inside which sensitive to static electricity. It can be a problem when the air humidity is low. Static can discharge through the electronic components causing invisible damage. Some basic methods to reduce the build up of static on your body are:

Keeping these simple habits will significantly reduce the risk of damaging components with electrostatic discharge.

2. Tools and materials required

Regarding which desoldering tool to use:

The best tool to use is a professional tool, like the Hakko FR-301. Most people will not have one available, so the next best thing is what I'll call a manual pump desoldering tool. The original design, which is getting a bit rare now, is the suction bulb desoldering iron.


There is also the more popular design, which is cross between a soldering iron and a solder sucker. Basically a soldering iron with hole in the tip that runs through to a spring loaded plunger in the handle.



3. Open the NES console and take out the motherboard

Turn the console upside down and remove six Philips-head screws and take the lid off. Then remove seven screws holding down the top RF shield.



Remove the last eight screws holding everything down, then take the motherboard out of the shell, remove the cartridge ejector mechanism (the slot can remain), unplug the left and right controller ports and the big blue power reset connector. All screws are alike except for a pair which are longer and silver coloured, marked with yellow arrows in the picture below.



Put everything aside except for the motherboard and identify the PPU (graphics chip). It's a 40 pin DIP IC labelled 'PPU' on the silkscreen text. The part number is RP2C02 for a NTSC console and RP2C07 for a PAL console.



4. Remove PPU and mount it on the NESRGB board

Use a desoldering tool to desolder the PPU. I recommend adding fresh solder to the pins on the bottom first as this tends to makes the old solder flow better.

If you are determined to do it without this tool, it is more difficult. You will need a soldering iron of at least 40W, preferably a temperature controlled soldering station. If the tip is worn out or corroded, replace it with a new one. You will also need a good solder sucker. Squirt a little bit of WD40 into the solder sucker before you start to improve it's performance.

Wiggle each pin with a pair of tweezers to make sure it's completely free if solder. If you have one pin that is difficult to free, try flowing fresh solder into the joint before desoldering it again. Pins 14, 15, 16, 17 are all connected together on the top layer of the motherboard the large amount of copper attached to these pins makes them more difficult to desolder than the others.

Once all the PPU pins can be wiggled freely, carefully pry the PPU out of the board with a flat head screwdriver. Inspect the pins to make sure there are no bits of the motherboard came with it. If you have some copper stuck to a PPU pin like in the picture below, you will need to investigate the damage, and possibly repair the motherboard. Many of the plated through holes that the PPU sits in are also vias that connect signals between the top and bottom layers of the PCB.



Clean excess solder from the PPU pins with solder wick and straighten the legs with an IC pin straightener or pair of pliers if necessary.

Inspect the holes in the PPU spot, especially pin 14-17, and remove excess solder with solder wick from the top side. Insert the round pin IC socket into the motherboard and solder it into position as shown.



Insert the pair of round pins strips into the socket.



Place the NESRGB board over the pins. If any of the orange ceramic disc capacitor are in the way, just bed them over slightly. Solder the end pin of each strip and look at the board from the side. If it all looks reasonably straight, then solder all 40 pins in place.



Carefully remove the NESRGB board from the socket. Use side cutters to trim the row of pins which will be under the PPU. They don't need to be cut flush with the board, halving them is fine.



Place the PPU on the NESRGB and solder the legs on the underside of the NESRGB board. Make sure the orientation mark on the PPU matches the mark on the NESRGB silkscreen (don't put the PPU in the wrong way around).



With the round pins and PPU soldered in place, the NESRGB board should look like this from the side.


5. Wire to motherboard

Put the NESRGB board back into the socket on the motherboard. Close solder jumper JP1, but leave JP12 and JP13 open.



The NESRGB needs to be connected to the controller signals (for the on-screen menu), the reset button (for in game reset), audio signals from the CPU and cartridge slot, and the original video signal output (for load detection).

NESRGB pad Motherboard location Pin name Notes
A (CPU audio input 1) CPU, U6 1 (Audio 1)
B (CPU audio input 2) CPU, U6 2 (Audio 2)
46 (cartridge audio input) Cartridge slot 54 (Exp 6) Optional
OVIN (original video input) RF modulator, yellow phono socket Centre pin Optional
2C (controller clock input) Player 1 controller P4 I 2 (Clock) Connector P4 I red wire
3L (controller latch input) Player 1 controller P4 I 3 (Latch) Connector P4 I orange wire
1D (controller data input) Player 1 controller P4 I 4 (Data) Connector P4 I yellow wire
RO (reset output) Power/reset assembly, blue connector P6 4 (Reset button) Connector P6 yellow wire

The photo below shows all points wired, with details further below. The notes section of the table above describes the colours of the wires Nintendo used for the console's cables, not the wires soldered in the photo below (which are coloured arbitrarily).

I have connected CPU pins 1 and 2 audio wires the adjacent resistor legs pads, but you could also solder to the CPU directly if you prefer.



The cartridge audio input - pad '46' on then NESRGB should be connected to cartridge pin 54. The easiest way to do so is to find pin 18, then solder to the via immediately above it which connects to its opposite, pin 54.



The Famicom (Japanese version of the NES with a different cartridge slot) console has dedicated audio pins on the cartridge slot and some Famicom games have extra sound synthesis hardware on the cartridge. It is possible to play Famicom games on the NES with an adapter or reprogrammable cartridge. Typically, the adapter needs to modified by connecting a wire between the pin 46 on the 60-pin Famicom cartridge slot to pin 54 of the 72-pin NES card edge. Pin 54 is an unused pin that connects to the expansion port only. Popular reprogrammable cartridges such an the Everdrive N8 For NES and Powerpak already output audio on pin 54.

Wiring the cartridge audio is optional. You can leave it off if you don't intend to play any Famicom games. 


The OVIN pad is wired to the original composite video output connection.



The OVIN (Original Video INput) as the name suggest is input on the NESRGB board where the original composite video signal may be connected. This allows the NESRGB board to automatically detect if the composite video is connected ('loaded') on power up and automatically switch to composite video mode. This feature is for front loading NES consoles only.

Wiring the OVIN is optional. You can leave it off if you don't intend to ever use the original composite video.


The best place to connect to the player 1 controller signals is on the back side of the motherboard. In the photo below I have connected the wires to the adjacent capacitor pads, but you could also solder to the connector directly. Clock is pin 2, Latch is pin 3, Data is pin 4.



The reset button is connected to the pin 4 of the large blue connector that connects to the power/reset switch board. In the photo below I have connected the wire to the adjacent capacitor, but you could also solder to the connector directly.




6. Wire and mount the AV connector

The kit is supplied with a mini-DIN socket for RGB video signals and a 3.5mm jack socket for audio. This compatible with my RGB SCART cable set and you can also buy a suitable cable from Retro Gaming Cables and possibly other third party suppliers. The other popular alternative is to fit a Nintendo style Multi Out socket, the same as found on the Super Nintendo and Nintendo 64 consoles. The guide splits into three parts here. One for the Mini-DIN, one for the Multi Out, and the third section briefly describes other alternative RGB connection. The guide converges for the final stage at the end. 

AV connector: 8 pin mini-DIN

The mini-DIN connector is the easiest one to mount - it requires only a circular hole. I use a separate connector for audio, but this is optional. There are audio pins on the mini-DIN socket than can be used instead. A separate connector for audio may result in lower distortion because there is less opportunity for the video signal to couple into the audio signals inside the cable. It also allows for the audio to be directly connected to an audio amplifier without going to the TV or scaler first.

I recommend this location on the rear of the bottom half of the shell, next to the RF output. Use a marker pen to mark the locations. They should be the same height as the RF connector vertically. Avoid the area in front of the screw boss.



Use a drill with a 3mm bit to drill a pilot hole where your marks are. Then drill the correct size hole for each connector with the step drill bit. The audio socket requires an 8mm hole and the mini-DIN socket a 12mm hole.



Insert the sockets into their respective holes.



Glue the sockets to the inside of the shell. I recommend two part epoxy glue for this. Make sure the min-DIN connector is around the right way with the notch at the top, and that the connector is not slightly rotated. There's nothing worse than a crooked DIN connector... Put some tape over the connectors to hold them in while the glue dries.

The audio connector does come with a nut, but it doesn't fit very well. It's much better to glue it in place.



Once the glue has dried you can solder the pin label board to the back of the mini-DIN. Take to put the pin label board on the right way. The circle on the silkscreen goes on the side with the connector, the text on the solder side.



Cut your hook-up wire into pieces 270mm (11 inches) long.

Wire it up according to this table.

NESRGB pad Mini-DIN socket pin label Notes
B B Red video
G G Green video
R R Red video
VS V 75 ohm sync signal (in RGB mode)
+5V +5 +5V power for SCART switching
GND GND Ground

NESRGB pad Audio socket Notes
AO pins 2 and 3 together (short tabs) Audio signal
GND 4 (long tab) Ground




AV connector: Nintendo style Multi Out

It's possible to fit a Multi Out socket so the NES uses the same RGB cable as the NTSC Super Nintendo. Nobody has made proper moulded Multi Out socket for the past twenty years or so, but there are some 3D printed ones available which are almost as good. This section will cover the one made by Laser Bear. They make two versions one is called Voultar NESRGB QSB FFC Kits - Snapfit for Front Loading NES, the other is called NES Front Loader Snap-fit Multi out. This guide features the former, but the mounting is the same for both. The only difference is one uses a flat flex cable to carry the signals and the other uses wires that must be soldered. Refer the the diagram below for the one that requires wires.



This is what it looks like when mounted to the rear of the console.



The first step is to choose a place to mount it. I generally recommend the rear of the console, on the opposite side to the RF box. If you are mounting the FFC version, make sure the chosen spot is not right behind a screw boss, as you will need some space to insert the FFC cable behind it. Use a marker and the plastic template provided to draw a rectangle to cut out.



Use a drill with a 3mm bit to drill a series of holes side by side around the inside of the rectangle.



Cut out the remaining plastic around the cut line with a pair of side cutters.



Use a file to finish the edges.



Insert the Multi Out connector, lock it in with the provided retention clip on the inside. Insert the edge finger PCB and secure it in place with the screw.

On the FFC version, the cable connects directly to the FFC connector J1 on the NESRGB board. Slide the cable lock on the connector back, insert the cable with the fingers facing up, then push the cable lock forward to keep it in place.




AV connector: Female SCART



There plenty of space on the rear of an NES console to mount a SCART connector, so it's a perfectly valid solution. Don't let anybody from the cult of Multi Out tell you otherwise. Suitable cables are still generally available. The downside is it requires cutting an irregular hole shape into the rear of console shell - it can be difficult to do in a way that looks good.

It should be wired up according the table below.

NESRGB pad SCART output female 21 pin socket
R (Pr/red/chroma video output) 15
G (Y/green video output) 11
B (Pb/blue video output) 7
VS (composite video/75 ohm sync output) 19
AO (audio output) 1, 3
+5V Connect to pin 16 through a 180 ohm resistor (RGB status)
GND (Ground) 4, 5, 9, 13, 14, 17, 18, 21

Do not connect SCART pin 16 (RGB status) to directly to the +5V power supply, it must have a resistor in series. This in necessary to put a TV set into RGB mode via SCART, don't leave it unconnected.

SCART pin 8 (Video status) is supposed to have 12V DC present to signal to the TV to go into AV mode. This is typically generated with a charge pump circuit and current limited to a few milliamps (in case of short circuit). In practice, it's almost never necessary. Pressing the AV button on the TV remote will achieve the same result, and it's likely that an TV set which is old enough to feature a SCART connector will spend all its time in AV mode, anyway. Digital video scalers ignore this pin. I recommend leaving it unconnected. Do not connect it to +5V as this will either do nothing at all (best case) or force the SCART TV into widescreen mode.

All ground pins should be connected. Some cables use only a couple of them, and you never know which ones.

You can use the following commonly available cables:


 SCART to composite video/audio cable. Typically there is an input and output set. Remember to use the output set.

SCART to component video/audio cable.

SCART to SCART cable. Normally used for RGB video/audio.

SCART to composite and s-video and audio adapter. You must use the one with the in/out switch and set it to out.

These ones are NOT SUITABLE:


 Composite and s-video and audio to SCART adapter (notice there is no in/out switch). This cannot be used for signals coming out of a SCART connector.

SCART to component video adapter. There are no audio connections, quite useless.

7. Test and set up OVIN

Once the AV port is wired up it's a good time to test the installation. Do the minimum assembly to get the NES console operating. That means put the cartridge eject mechanism back on, plug in the controller port 1 and the blue connection to the power/reset button board. Plug in TV, power, game cartridge, controller and play a game or two.



To activate the on-screen menu: on the controller for player 1, press d-pad down + select together, hold for one second then release both. The on-screen menu in not accessible when the NESRGB board is in composite video mode, only in s-video, RGB, or component video output mode.

Now you are going to calibrate the OVIN input, so it works correctly on your console. The calibration procedure will measure the voltage on the OVIN pad during a power up condition without anything connected to the original composite output, then again with a TV set connected. It requires turning the console off and on a couple of times.

To activate the on-screen menu: on the controller for player 1, press d-pad down + select together, hold for one second then release both. Once the menu comes up, tap down on the d-pad until you get to 'Calibrate video load'.



Press and hold right on the d-pad for a two seconds to unlock. Then tap right again to change it from 'Off' to 'On'. Press select to save.

The calibration process has started. Turn the console off.



Nothing is connected nothing connected to the original video output. Turn the console back on again.



Once it comes back on it will show the following. Turn the console off again.



Connect video lead between the console and the TV (it doesn't have to be the same TV set you currently have the console connected to). Turn the console on.



If you activate the menu, the status should have changed from 'Off' to 'Success'.



Now you can test the feature. Connect the console to the TV with the original video connection only. The NESRGB board should come up in composite video mode automatically.

8. Reassemble the NES console

Take out the motherboard once again, unplug player 2 controller and the power/reset board cables, and place the metal RF shield under the motherboard, an plug the two cables back in. Screw eight screws back in, two on the RF modulator and six on the cartridge mechanism. Refer the diagram at the start of the guide for exact locations if you cannot remember.



Replace the top half of the RF shield and put seven screws in it. Pop the top half of the shell back on and the remaining six (or however many screws are left over) go in the bottom.

Created 15/8/2026