Nintendo Entertainment System Capacitor Replacement Guide

Nintendo Entertainment System
	Nintendo Entertainment System (front-loading model)
Specifications
Manufacturer	Nintendo
Type	Home video game console
Released	1983 (JP, as Famicom), 1985 (NA/EU, as NES)
Discontinued	1995 (worldwide)
Intro price	US$179.99 (NA launch, 1985)
CPU	Ricoh 2A03 (MOS 6502 core) @ 1.79 MHz (NTSC) / 1.66 MHz (PAL)
Memory	2 KB RAM, 2 KB video RAM
Storage	ROM cartridge (up to 1 MB)
Display	256×240 px (NTSC), 256×240 px (PAL); 48 colours, 25 on screen
Sound	5 channels (2 pulse, 1 triangle, 1 noise, 1 DPCM)
Dimensions	25.4 × 20.3 × 7.6 cm (front loader)
Weight	1.4 kg (front loader)
OS / Firmware	None
Predecessor	Color TV-Game
Successor	Super Nintendo Entertainment System
Codename	AVS (prototype), Famicom (Japan)
Model no.	NES-001 (front loader), NES-101 (top loader)

Specifications
Manufacturer
Type
CPU
Memory
Storage
Display
Sound
OS / Firmware

The Nintendo Entertainment System (NES) is an 8-bit home video game console developed and manufactured by Nintendo. Released as the Family Computer (Famicom) in Japan in 1983 and as the NES in North America and Europe from 1985, it became one of the most influential and best-selling consoles of its era.

🧠 Architecture and Processor

The NES is powered by the Ricoh 2A03 CPU (a custom MOS 6502 derivative) running at 1.79 MHz (NTSC) or 1.66 MHz (PAL). The CPU integrates both the main processor and the audio processing unit (APU), providing five audio channels.

💾 Memory and Storage

The system features 2 KB of onboard RAM and 2 KB of video RAM. Game data and additional hardware are supplied via ROM cartridges, with later games including extra RAM, mappers, and co-processors.

🖥️ Display and Graphics

The NES outputs a resolution of 256×240 pixels (NTSC/PAL), supporting up to 25 simultaneous colours from a palette of 48. Graphics are handled by the Picture Processing Unit (PPU), which supports hardware sprites and scrolling.

🔊 Sound Capabilities

The integrated APU provides five sound channels: two pulse wave, one triangle wave, one noise, and one DPCM (sample playback) channel.

🎮 Input/Output and Expansion

The NES features two controller ports, an expansion port (underside, rarely used outside Japan), RF and composite AV outputs, and a 72-pin cartridge slot (60-pin in Famicom).

🧰 General Maintenance

Regular maintenance includes cleaning cartridge contacts, controller ports, and ensuring the power supply delivers stable voltage. The NES is known for its "blinking red light" issue, often caused by dirty or worn cartridge connectors.

🧾 PCB Schematics & Service Guide

Official service manuals and third-party schematics are available for both NES-001 and NES-101 models. These detail board layouts, test points, and component values.

📷 Motherboard Images

NES-001 motherboard (front)

NES-001 motherboard (front)
NES-001 motherboard (back)

NES-001 motherboard (back)

📚 Technical Documentation

📷 Gallery

Nintendo Entertainment System (front loader)
NES-101 (top loader)

NES-101 (top loader)
NES Game Pak (cartridge)

🧪 Related Pages

General Maintenance

Clean cartridge slot with isopropyl alcohol and a soft brush.
Inspect and clean controller ports.
Check power supply output (9V AC, 850mA for NES-001).
Replace 72-pin connector if games fail to load reliably.

PCB Schematics & Service Manual

Apple Service Manual

Not applicable to NES.

Logic Board & Analog Board Schematics

See above NES-001 and NES-101 service manuals.

Capacitor Replacement Guide

Over time, electrolytic capacitors in the NES may degrade, leading to video, audio, or power issues. Replacing these capacitors can restore system stability and performance.

Tools and Materials Needed

Soldering iron (fine tip)
Solder sucker or desoldering braid
Lead-free solder
Replacement capacitors (see table below)
Phillips screwdriver
Isopropyl alcohol and cotton buds

Common NES Capacitors (NES-001)

Reference	Value	Voltage	Type	Location
C6	220µF	16V	Electrolytic	Power input (DC in)
C7	10µF	16V	Electrolytic	Audio circuit
C10	1µF	50V	Electrolytic	Video circuit
C11	100µF	6.3V	Electrolytic	Power filtering
C13	47µF	16V	Electrolytic	Power filtering

Note: Capacitor values may vary by board revision. Always verify before ordering replacements.

Replacement Procedure

Unplug the NES and remove all cables and cartridges.
Open the case by removing the six Phillips screws on the underside.
Remove the shielding and motherboard.
Locate the capacitors to be replaced (see table above).
Desolder the old capacitor, noting polarity (long leg = positive).
Insert and solder the new capacitor, matching polarity.
Trim excess leads and clean any flux residue.
Reassemble the NES and test for proper operation.

Retrobrite

Yellowed NES plastic can be restored using hydrogen peroxide and UV light ("retrobrite" process). Always use gloves and eye protection.