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

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

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

**NES Electrolytic Capacitors**
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

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

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.