1996 Nintendo 64 Repair, Restoration, & Modification

My lovely wife kindly bought me six vintage games consoles for Christmas 2023, all in unknown or non-working condition, including my first Nintendo 64.

The Nintendo 64 is a home video game console developed by Nintendo – the successor to the Super Nintendo Entertainment System (SNES), it was the last major home console to use cartridges as its primary storage format until the Nintendo Switch in 2017. It competed primarily with the Sony PlayStation and the Sega Saturn. The Nintendo 64 was discontinued in 2002 following the 2001 launch of its successor, the GameCube – it was critically acclaimed and remains one of the most recognisable video game consoles.

Nintendo 64s aren’t particularly rare, and you can pick them up in non-working condition for quite cheap – they go for quite a bit when refurbished and modified, though, and the rarer variants can fetch a huge amount of money. Their nostalgia value and interesting game library make them quite collectible.

On its arrival, it seemed to be in quite good physical condition. I bought a modern power supply and a HDMI adapter suitable for stock N64s, then tried it out – unfortunately, it would only output a blank black screen with any of the three cartridges that I had.

The first step was to disassemble the unit and check over everything inside.

Disassembling the N64

The N64 is easy to dismantle with basic tools: remove the Jumper Pak or memory expansion from its slot using a spudger; remove the six 4.5mm security screws around the perimeter of the underside of the case.

With the case opened, you get your first look inside the console – everything seemed to be original and pretty much untouched.

The mainboard and RF shielding are held into the bottom case with two long Philips screws on each side of the game cartridge slot, two long Philips screws on each side of the expansion slot, five Philips screws around the perimeter of the RF shield, one Philips screw at the bottom-right of the expansion slot, and four Philips screws (two each) on the two rear I/O port strain reliefs.

To remove the heatsink crossbar, there are ten Philips screws around its centre, and four Philips screws (two black, two brass) holding in the expansion slot shield.

Black Screen Repair

Black screen faults are apparently quite common problem on the N64, typically caused by a bad connection with the game cartridge or memory expansion / Jumper Pak.

I tested the basics first, power and reset: all power rails seemed OK (3.185Vdc and 12.35Vdc after the two-gang power switch, 5.05Vdc for the video connector from U13, and 2.55V from U12); the reset line out of the reset switch also seemed OK.

The mainboard was quite dusty, so I cleaned the reset switch, power switch, game cartridge slot, and expansion port with contact cleaner; the game cartridge port was full of thick, long hairs (yuck), which I carefully pulled out using tweezers; I also cleaned the Jumper Pak connections with contact cleaner, and cleaned the game cartridge connector with some cotton buds and acetone until they came up nice and shiny.

I tested the console again, and it now seemed to boot up fine.

With the console working, I wanted to perform some preventative maintenance (replacing all of the SMD aluminium electrolytic capacitors on the mainboard), as well as some “tasteful” modification (fitting an RGB video encoder to bring the N64 up to the same A/V standard as the SNES and GameCube, with better image quality for modern displays).

Mainboard Servicing

Aluminium electrolytic capacitors are commonly used for filtering, smoothing, and decoupling in both high- and low-voltage electronics. They are quite cheap in comparison to their solid-electrolyte counterparts (such as tantalum and polymer electrolytics), so are very common in consumer electronics.

Their useful lifetime is highly dependent on the specific application that they are used in (i.e. frequency, ripple current) and temperature, as well as the manufacturer and series of the specific component. They typically comprise aluminium windings which are coated with a liquid electrolyte, which can dry out over time (negatively affecting the performance of the capacitor, often causing them to fail dead-short), or even leak out and cause corrosion to the PCB and surrounding components.

SMD aluminium electrolytic capacitors are common, well-documented failure points in other pieces of equipment from the 1990s (i.e. Amiga 600, Amiga 1200, Apple PowerBooks, Apple Macintosh Classic / Classic II / SE / SE/30, etc) – I don’t think that the N64 has been affected by this as of the time of writing, but it doesn’t hurt to be proactive.

There are several production variants of the N64 mainboard, each of which have different electrolytic capacitor values and locations, so take note of which you have.

This one is an early PAL board, marked “NUS-CPU(P)-01”. This is easy enough to recap as it only has 16 surface-mount electrolytic capacitors:

• C24: 33uF 25V
• C25: 10uF 16V
• C26: 10uF 16V
• C28: 33uF 25V
• C33: 68uF 10V
• C34: 10uF 16V
• C73: 68uF 10V
• C81: 68uF 10V
• C128: 10uF 16V
• C130: 68uF 10V
• C131: 68uF 10V
• C134: 68uF 10V
• C140: 68uF 10V
• C141: 68uF 10V
• C142: 33uF 25V
• C145: 68uF 10V

I decided to use tantalum electrolytic capacitors, an equivalent to aluminium electrolytic capacitors – these use a solid electrolyte, meaning that they will not physically leak.

I couldn’t find any commercially available tantalum capacitor packs for this version of the N64 mainboard, so I just made up my own by noting the specifications of all of the electrolytic capacitors on the board, and ordering a set of high-quality known-brand parts.

When substituting electrolytic capacitors, the capacitance needs to be the same, and the voltage rating can be the same or higher (within reason) – when you’re going through all this effort to recap something, be sure to use high-quality replacements.

The original parts can be removed using a hot air rework station with kapton tape and aluminium foil to protect the surrounding areas, or by carefully twisting them off using needle-nose pliers (this technique may not be suitable if the pads are damaged, as they could delaminate from the board – and push downwards, don’t pull upwards!).

The pads can then be cleaned up using new leaded solder and either desoldering braid or a desoldering station. The board should then be thoroughly cleaned to remove any leaked electrolyte and leftover flux, using isopropyl alcohol and an ESD-safe brush.

New parts can then be installed as required.

When fitting new electrolytic capacitors, you must take care to ensure that the value, voltage rating, and orientation of the new capacitor are correct – electrolytic capacitors are polarised, so must be installed the correct way around, else they’ll get hot when powered on (and probably explode). The polarity is marked on the case: for aluminium electrolytic capacitors, the negative side is usually shown by a white stripe (for through-hole) or a black bar (for SMD); for tantalum capacitors, the positive side is usually shown by an orange or white bar (for SMD). This catches a lot of people out!

You can’t always trust the orientation markings on the PCB silkscreen (if it even has them, not all boards do), as sometimes mistakes were made in the design from the factory (take the PCB layout of the audio circuit on the Commodore CD32, for example), so care must be taken to match the orientation of the new capacitor with the original. Make sure to take lots of “before” pictures for reference, and double-check throughout.

RGB Video Modification

The Nintendo 64 uses the same “MultiAV” connector as the SNES and GameCube, however it lacks an RGB video output, having only S-Video and composite video. RGB video gives a clear, high-quality output compared to these, and is more suitable for use with up-scalers and modern high-resolution displays.

There are a few options for reinstating the RGB video output – NTSC N64s can use a simpler semi-passive RGB modification, whereas PAL N64s require an active RGB modification like the TW-N64RGB kit, which is the one that I used.

The TW-N64RGB kit is relatively easy to install, following the manufacturer’s comprehensive installation guide – the version that I bought came with a ribbon cable with a connector on each end, which made installation much cleaner and allowed for the cable to be easily removed from either end if required.

I also wired up an internal de-blur control switch using a small two-way switch that I had in my stock of switches – this ties “SW” to “GND” when disabled.

I tested the installation of the modification before reassembling the console, and it seemed to work well – the video quality via an RGB SCART cable was far better.

Reassembly and Testing

The console reassembly is just the reverse of its disassembly.

After its modifications and preventative maintenance, the N64 looked great and worked perfectly! I even bought an SD card cartridge to try out even more of its game library.

I also fitted an original Nintendo Expansion Pak, which adds an extra 4MB RAM (8MB total) – this is utilised by several N64 titles, such as Donkey Kong 64.