Nintendo Entertainment System Capacitor Replacement Guide
Replacing the electrolytic capacitors in a Nintendo Entertainment System (NES) restores power stability, reduces video/audio glitches, and can resolve random resets or startup failures. The NES uses robust Japanese capacitors, but after 35+ years, original parts are often dried out or leaky, especially in high-heat areas near the voltage regulator and RF modulator.
Visual Inspection & Failure Signs
[edit | edit source]- Bulging or leaking cans – especially C6 (main filter) and C22 (audio/video decoupling).
- Corrosion or brown residue – at the base of capacitors, often near the power supply section.
- Vertical lines or flicker on video – commonly linked to failing C10 or C12.
- Audio hum or distortion – dried-out C22 or C24 can inject noise into the audio path.
- Random resets or failure to power on – C6 or C7 (power rail filters) with high ESR.
If any capacitor shows visible failure, it’s best practice to replace all electrolytic capacitors on the mainboard.
NES Mainboard Capacitor List
[edit | edit source]The NES mainboard (NES-CPU-xx) uses through-hole aluminium electrolytics. Always verify values against your board’s silkscreen, as minor revisions exist.
NES-CPU-05/07/09 Mainboard
[edit | edit source]| Board Ref | Capacitance | Voltage | Purpose / Rail |
|---|---|---|---|
| C6 | 1 000 µF | 16 V | Main +5 V input filter (from AC adapter) |
| C7 | 220 µF | 16 V | +5 V regulator output smoothing |
| C10 | 47 µF | 16 V | PPU +5 V decoupling (video stability) |
| C12 | 10 µF | 16 V | CPU +5 V decoupling |
| C22 | 10 µF | 16 V | Audio output DC blocking |
| C24 | 1 µF | 50 V | Audio path coupling (to RF modulator) |
| C25 | 100 µF | 16 V | RF modulator supply filter |
Additional Notes
[edit | edit source]- Some revisions may use slightly different values for C7 or C25 (e.g., 330 µF or 220 µF). Always match or slightly exceed voltage ratings.
- Ceramic and tantalum capacitors (e.g., C11, C13) rarely fail and do not need routine replacement.
- If your NES has severe corrosion or liquid damage, inspect for lifted pads or broken traces before recapping.
Replacement Tips
[edit | edit source]- Use 105°C rated capacitors for maximum longevity.
- Observe polarity: the long lead is positive, and the negative stripe on the body must match the board’s marking.
- Desolder one capacitor at a time to avoid confusion.
- Clean any leaked electrolyte with isopropyl alcohol before installing new parts.
- After recapping, test the NES with a known-good power supply and game cartridge.