Nintendo 64 Maintenance Guide

Nintendo 64 NUS-CPU-03 mainboard, top

The Nintendo 64 was made from 1996 to 2002, so the youngest consoles are over twenty years old. Nintendo's service-centre manual of June 2002 covers its disassembly and parts list but gives no schematic or component values. Nintendo's maintenance advice for owners is in the consumer instruction booklet, and the most detailed circuit reference is RDC's schematic of the NUS-CPU-03 and -04 mainboards.

For per-revision capacitor lists see Nintendo 64 Capacitor Replacement Guide; for fault-finding see Nintendo 64 Troubleshooting Guide.

Opening the console

Six 4.5 mm Gamebit screws in the base hold the top cover. The screws inside are JIS cross-head: use a JIS driver, or an iFixit cross-head bit, which iFixit makes to fit JIS heads. Cartridges take a 3.8 mm Gamebit and controllers a JIS #1.

1. Switch off, unplug the supply from the wall and pull the AC Power Supply out of the console with its release button pressed.
2. Remove the Jumper Pak or Expansion Pak.
3. Undo the six Gamebit screws in the base and lift off the top cover.
4. Remove the metal shields and brackets, then the screws holding the board, as in iFixit's motherboard guide.

The board carries heatsinks under its shields. N64brew notes that a board can be run on the bench for a while without them, but not indefinitely.

Power supply

The AC Power Supply (NUS-002) gives +3.3 V at 2.7 A and +12 V at 0.8 A on a six-pin connector with three ground pins. No +5 V comes from the supply. Pin numbers differ between the plug and the socket, so find the rails with a meter rather than trusting a pinout: 12 V on a pin that should carry 3.3 V will damage the board.

Nintendo advises leaving the supply plugged into the console, even in storage, to save wear on the connector, and unplugging it from the wall instead. North American supplies are built for 120 V and European ones for 220-240 V; their primary reservoir capacitors are rated 200 V and 400 V respectively, and the supplies are not interchangeable.

Warning: the supply's primary side runs at mains voltage, and the primary reservoir can hold a dangerous charge after the supply is unplugged. Discharge it through a suitable resistor and confirm with a meter before touching the board. Capacitor lists for each supply board are on Nintendo 64 Capacitor Replacement Guide.

Supplies on the mainboard

On-board supplies, from the NUS-CPU-03/04 schematic

Part	Function	Expected
P4	Supply input	+3.3 V and +12 V
SW1	Power switch; breaks both input rails
U13 (78M05)	+5 V regulator, fed from +12 V	+5 V
U12 (PQ7VZ5)	RDRAM termination supply, fed from +3.3 V	Vterm 2.56 V
R25, R35	Divider from Vterm	Vref 1.92 V
D3, R31 (75 Ω)	Power LED, from +3.3 V

The schematic shows no fuse on the mainboard. The CPU, RCP, RDRAM and PIF run from +3.3 V; +5 V and +12 V are used mainly by the audio and video output stages.

Capacitors

All the mainboard electrolytics are surface-mount cans, 13 to 18 of them depending on the board revision. Read the revision (NUS-CPU-xx, NUS-CPU(P)-xx or NUS-CPU(R)-01) off the board before ordering parts, and use the lists on Nintendo 64 Capacitor Replacement Guide.

Jumper Pak and Expansion Pak

One of the two must be in the Memory Expansion slot or the console will not operate. The Jumper Pak (NUS-008) only terminates the RDRAM bus; the Expansion Pak (NUS-007) adds 4 MB of RDRAM. Nintendo supplied a Jumper Pak Ejector (NUS-012) with the Expansion Pak for pulling the Jumper Pak. A pak left out or half-seated after a repair looks like a dead console.

Cleaning

Nintendo sold a cleaning kit for the N64 outside Japan, with a Control Deck Cleaner (NUS-014), a Controller Cleaner (NUS-015) that fits the controller's pak slot, and a Cleaning Wand (NUS-016) for Game Pak and Controller Pak contacts.

• Before loading a Game Pak, check its edge connector for foreign material, as Nintendo's booklet says. Clean dirty contacts with isopropyl alcohol on a lint-free swab and let them dry.
• Clean the cartridge slot, Memory Expansion slot, controller sockets and multi-out with low-pressure air, a soft brush and isopropyl alcohol, with the console unplugged.
• Clean the case with a damp cloth and a little mild detergent.

Controller

For sticking buttons, Nintendo's procedure is: disconnect the controller, dip an unused toothbrush in hot tap water (not boiling, and with no soap or detergent), shake it off, scrub around the sides of the buttons, towel it dry and leave it to air-dry for at least two hours. Do not pour liquid on the controller or submerge it.

The analogue stick is a self-contained module on a six-pin connector, so a worn one can be swapped as a unit. A stick that has gone loose has a worn plastic bowl inside the module. iFixit's guide rebuilds the bowl with epoxy putty shaped with a marble, then greases it. A stick that drifts may only need re-centring: leave it centred at power-on, or hold L and R and press START with the stick released.

Batteries

The console has no battery. Cartridges that save to SRAM, and Nintendo's Controller Pak, keep their saves with a CR2032 cell. To change a cartridge cell without losing the save, wire a second CR2032 across the save-RAM supply first so the RAM stays powered while the old cell is removed. See Battery Refurbishment.

The Rumble Pak (NUS-013) runs from two AAA cells. Remove them for storage. iFixit's guide clears corrosion from the contacts with a flat screwdriver and a cotton bud and warns against using water. See Battery Explosion, Capacitor or Corrosion Damage.

Multi-out connector

If video or audio cuts out when the lead is moved, iFixit's fix is to reflow the six contacts where the multi-out connector meets the mainboard.

Tools

• 4.5 mm Gamebit (console) and 3.8 mm Gamebit (cartridges)
• JIS cross-head drivers, including JIS #1 for the controller
• ESD wrist strap and a soft anti-static brush
• Isopropyl alcohol (99 %) and lint-free swabs
• Digital multimeter
• Hot-air station or a fine iron and flux for surface-mount capacitors

See Recommended Tools.

Routine checks

Nintendo set no service interval for the N64. When a console comes in, or before a long session on one of unknown history:

1. Measure both supply rails at the plug before connecting it to the console.
2. With the console running, check +5 V at U13's output, Vterm at 2.56 V and Vref at 1.92 V.
3. Reseat the Jumper Pak or Expansion Pak.
4. Clean the cartridge contacts and slot if games need more than one insertion to start.
5. Check that the save battery still holds in any battery-backed cartridges.

Related pages

• Nintendo 64
• Nintendo 64 Capacitor Replacement Guide
• Nintendo 64 Troubleshooting Guide
• N64 NUS-CPU-03-04 Schematic
• Recommended Tools
• Capacitor Failure Symptoms