Nintendo Entertainment System Capacitor Replacement Guide

The front-loading Nintendo Entertainment System (NES-001) mainboard carries only three electrolytic capacitors. Almost everything a recapper needs to replace on an NES is inside the combined power supply / RF modulator module that bolts to the mainboard, and on the top-loader (NES-101) the picture is different again. This guide gives the capacitor lists by board and by module, with the designators taken from Nintendo's own schematic and from boards that people have actually read.

NES-001 power, A/V and RF switch sheet. The console's regulator and reservoir capacitors live in the power/RF module, not on the mainboard.

What is and is not electrolytic

The NES-001 mainboard is overwhelmingly ceramic-decoupled. The schematic shows forty-four capacitor positions on the control deck PCB, of which all but three are 0.1 µF or smaller: banks of 0.01 µF supply decouplers beside each IC, 330 pF noise suppressors on the controller input lines at C27–C37, and a handful of small values around the oscillators.^[1] Nintendo's service literature confirms the function of that bank: the input section "consists of U7 and U8 (40HC368s), DA1 through DA4, capacitors C26 through C37, BC1, BC2, RA1 and RA2", and provides "noise and spike protection on the input lines".^[2]

Ceramic capacitors of those values do not dry out and are not a routine replacement item. Replacing them achieves nothing and risks lifting pads on a thirty-five-year-old board.

NES-001 (front loader) mainboard

These three parts are the entire electrolytic content of the NES-001 control deck PCB. The values are identical on the hosted schematic and in Console5's list, which was compiled from physical boards — two independent readings agreeing on all three positions.^[1]^[3]

**NES-001 control deck PCB — electrolytic capacitors**
Designator	Value	Voltage
C1	100 µF	6.3 V
C9	2.2 µF	50 V
C23	1 µF	50 V

C8 and C9 sit in the reset circuit around U9 (74HCU04). Nintendo's own fault table lists "Defective C8 or C9" as a probable cause of no reset with an otherwise normal display, with the repair given as "Replace C8/C9" — so C9 is worth attention even where the board looks healthy. C8 is a 0.1 µF ceramic and will rarely be the culprit.^[2]^[1]

NES-001 power supply / RF modulator module

Nintendo describes the module plainly: the "Power Supply Section" is "contained in the RF Modulator" and "provides all of the operating voltages for the CPU PCB, gamepak and accessory devices (like controllers)". It also puts a 10 V DC signal onto the RF output, which is what switches the NES-003 RF switch away from the aerial when the console is turned on.^[2]

This is where the reservoir capacitor, the rectifier and the 7805-class regulator live, and it is where an NES recap actually happens. Several modules were used and they are not interchangeable lists — identify yours before ordering parts.^[3]

Alps modules with a BA20-type bridge rectifier

**Alps power/modulator module — green PCB with floating capacitor**
Designator	Value	Voltage	Note
C19	1 µF	50 V
C30	2200 µF	25 V	Main reservoir
C33	1 µF	50 V
C34	100 µF	6.3 V
(unmarked)	1 µF	50 V	Across the regulator input and ground. Any 1–100 µF part rated 16 V or higher is acceptable here

**Alps power/modulator module — brown PCB**
Designator	Value	Voltage
C1	10 µF	35 V (25 V is adequate)
C21	2200 µF	25 V
C23	10 µF	35 V
C25	100 µF	10 V
C29	1 µF	50 V

Alps modules with a four-diode discrete bridge

**Alps power/modulator PCB FR853**
Designator	Value	Voltage	Note
C1	10 µF	16 V	PAL boards only
C21	2200 µF	25 V	Main reservoir
C23	100 µF	25 V
C25	100 µF	10 V
C29	1 µF	50 V
C34	10 nF	—	Ceramic disc, listed for reference. Burnt C34 has been reported repeatedly on PAL modules
C35	1 µF	50 V
C36	10 µF	16 V

**Alps power/modulator PCB SH-SH5 / FS074**
Designator	Value	Voltage
C21	2200 µF	25 V
C23	100 µF	25 V
C25	100 µF	10 V
C29	1 µF	50 V
C36	10 µF	16 V
C37	1 µF	50 V

This board is a re-layout of the FR853 with several capacitors turned round. Check the silkscreen polarity marks against the old parts before you desolder anything.^[3]

Alps R22 (French RGB NES)

**Alps R22 module**
Designator	Value	Voltage
C1	10 µF	16 V
C3	22 µF	16 V
C9	10 µF	16 V
C19	2200 µF	25 V
C20	100 µF	16 V
C22	10 µF	25 V
C23	100 µF	10 V
C24	10 µF	25 V

Mitsumi modules

**Mitsumi power/modulator PCBs**
Designator	TDK-T12V	MTM-8V-0 / VIX	TDK-T31V
C2	10 µF 16 V	—	—
C5	—	10 µF 35 V (25 V is adequate)	—
C6	10 µF 16 V	—	10 µF 16 V
C20	—	2200 µF 25 V	—
C21	—	100 µF 16 V	2200 µF 25 V
C22	—	—	100 µF 16 V
C24	—	100 µF 10 V	—
C25	—	—	100 µF 10 V
C26	2200 µF 25 V	—	—
C29	100 µF 16 V	—	—
C31	100 µF 25 V	—	—
C32	10 µF 16 V	—	—

A T31V variant exists with a ferrite choke between the DC jack and the bridge, on which the capacitor numbering is shifted. If your board has that choke, do not assume the designators above apply.^[3]

NES-101 (top loader)

The top loader is a different machine electrically. Console5 documents three board revisions and gives a capacitor list for the first.^[4]

**NESN-CPU-01 (1993)**
Designator	Value	Voltage	Note
C1	100 µF	6.3 V
C3	1 µF	50 V
C11	0.47 µF	50 V
C13	1500 µF	25 V	The silkscreen says 1000 µF, but only 1500 µF parts have been observed fitted
C14	1 µF	50 V

No published capacitor list exists for the later NESN-CPU-JI0-01 (1993) or NESN-CPU-AV-01 (1994) boards. If you have one of those, read your own board and do not substitute the list above — the boards differ enough that the chip complement changes (the JI0 and AV boards add a separate VRAM at U4 and drop a 74LS373 for a BU3266S or BU3270S).^[4]

Removing the power/RF module without wrecking the mainboard

The five signal and power pins that join the module to the NES-001 mainboard have traces on the top side of the mainboard only. The obvious approach — desoldering all five from underneath the mainboard and pulling the module off complete with its pins — risks tearing a via out, leaving a signal missing when you put it back.

Console5's method avoids this: take the top shield off the power module, desolder the five pins at the module end rather than at the mainboard, then release the ground tabs. That leaves the pin-to-mainboard joints undisturbed and inspectable, and the module-side traces are accessible from the top so a lifted via there is harmless.^[3]

Replacement parts

Use 105 °C rated parts. Low-ESR types are appropriate for the reservoir and the regulator output; there is nothing on these boards that needs an exotic capacitor.
Match or exceed the original voltage rating. Do not fit a 16 V part in a 25 V position on the power module — the reservoir sits on the rectified, unregulated side of a supply that is well above its nominal figure at light load.
Observe polarity. On radial parts the longer lead is positive and the stripe on the can marks the negative lead.
Clean any leaked electrolyte with isopropyl alcohol before fitting new parts, and inspect for lifted pads and eaten traces underneath.

See Recommended Tools for soldering equipment, and Capacitor Failure Symptoms for how failing capacitors present.

References

↑ ^1.0 ^1.1 ^1.2 NES-001 Schematic (Electronix Corp. redraw by N. Schenk), hosted at File:NES-001.pdf. Capacitor designators and values read directly from the drawing: C1 100 µF, C9 2.2 µF, C23 1 µF; every other position is 0.1 µF or smaller. The drawing also gives the RP2A03 pin assignments and the 21.47727 MHz crystal at X1.
↑ ^2.0 ^2.1 ^2.2 Nintendo of America, NOA Independent Servicer Technical Training Workbook, Rev. 11/90 (part no. 21531), hosted at NOA Independent Servicer Technical Training Workbook. Control Deck "Malfunctions and Probable Causes" table, workbook pp. 54–55; Control Deck testing procedure, p. 53; RF switch theory of operation, p. 56; System Overview, p. 6; board section breakdown and test-point waveform plate, unnumbered pages near the end of the workbook.
↑ ^3.0 ^3.1 ^3.2 ^3.3 ^3.4 Console5 TechWiki, Nintendo NES-001 — https://wiki.console5.com/wiki/Nintendo_NES-001 . Secondary source: a community wiki whose capacitor lists are compiled from physical boards rather than from manufacturer documentation. Used here for capacitor values and voltage ratings, the chip map, the test-point list and the power/RF module variants.
↑ ^4.0 ^4.1 Console5 TechWiki, Nintendo NES-101 — https://wiki.console5.com/wiki/Nintendo_NES-101 . Secondary source, compiled from physical boards. Used for the NESN-CPU board chip maps, the NESN-CPU-01 capacitor list and the 68-of-72 populated pin count.

[nessch-1] 1.0 ^1.1 ^1.2 NES-001 Schematic (Electronix Corp. redraw by N. Schenk), hosted at File:NES-001.pdf. Capacitor designators and values read directly from the drawing: C1 100 µF, C9 2.2 µF, C23 1 µF; every other position is 0.1 µF or smaller. The drawing also gives the RP2A03 pin assignments and the 21.47727 MHz crystal at X1.

[noa-2] 2.0 ^2.1 ^2.2 Nintendo of America, NOA Independent Servicer Technical Training Workbook, Rev. 11/90 (part no. 21531), hosted at NOA Independent Servicer Technical Training Workbook. Control Deck "Malfunctions and Probable Causes" table, workbook pp. 54–55; Control Deck testing procedure, p. 53; RF switch theory of operation, p. 56; System Overview, p. 6; board section breakdown and test-point waveform plate, unnumbered pages near the end of the workbook.

[c5nes-3] 3.0 ^3.1 ^3.2 ^3.3 ^3.4 Console5 TechWiki, Nintendo NES-001 — https://wiki.console5.com/wiki/Nintendo_NES-001 . Secondary source: a community wiki whose capacitor lists are compiled from physical boards rather than from manufacturer documentation. Used here for capacitor values and voltage ratings, the chip map, the test-point list and the power/RF module variants.

[c5nes101-4] 4.0 ^4.1 Console5 TechWiki, Nintendo NES-101 — https://wiki.console5.com/wiki/Nintendo_NES-101 . Secondary source, compiled from physical boards. Used for the NESN-CPU board chip maps, the NESN-CPU-01 capacitor list and the 68-of-72 populated pin count.

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