Super Famicom Maintenance Guide
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Maintenance of the Super Famicom (SHVC-001): power, the cartridge connector, Nintendo's diagnostic table, the GPM board changes, ports, cleaning and disassembly. Nintendo's service figures come from two documents hosted here: the Japanese Famicom / Super Famicom / Game Boy service manual of 1992,[1] and Playtronic's Brazilian Super NES manual, which documents the same SHVC-CPU-01 board.[2]
Power
[edit | edit source]The Super Famicom runs from 10 V DC. Its adapter is the HVC-002, shared with the Famicom: AC 100 V in, DC 10 V 850 mA out, centre negative.[3] Nintendo gives the HVC-002's normal off-load output as DC 13.5 ± 1.5 V, so a reading of 12 to 15 V with no load is correct.[1]
| Contact | Function |
|---|---|
| Outer sleeve | +10 V DC |
| Centre pin | 0 V |
Most modern 10 V adapters are centre positive. Check the polarity before using one.
Do not use an NES or European SNES adapter. The NES adapter's output is AC,[3] and Martin Korth's fullsnes gives the European SNES supply as 9 V AC, rectified inside that console.[4]
Inside the console
[edit | edit source]Nintendo's SHVC power circuit takes the input through a choke, a fuse and a series diode to a reservoir capacitor and the power switch, then a 7805 regulator with 13–14 V in and 5 V out.[1] Playtronic's manual describes the outputs as a regulated Vcc of 5 V and an unregulated Vs of 7 V for the audio amplifier.[2] The NTSC redraw of the schematic labels VS as 9 V, and fullsnes says the console runs without that supply but makes no sound.[5][4]
The 7805 is U12 on the SHVC-CPU-01 and the SNS-CPU-GPM, -RGB and -APU boards, and U9 on the 1CHIP boards.[6] The 5 V supply is the only logic supply.[4]
The fuse
[edit | edit source]F1 is a 1.5 A axial fuse, listed by both Nintendo manuals, and it heads Nintendo's list of causes for a dead console.[1][2]
Nintendo's diagnostic table
[edit | edit source]Playtronic's manual prints Nintendo's control deck diagnostic table, with the probable causes in order of priority. Its preface: before any repair, take the unit apart and inspect the board for damaged or missing components or traces, solder defects, dirt and corrosion; do not try to clean the 62-pin connectors, replace them.[2][6]
| Malfunction | Probable causes, in order |
|---|---|
| Solid colour screen (including a black screen) | 62-pin connector; sound module; poor solder; U1 (CPU); U3 (PPU2); U6 (WRAM); U2 (PPU1); U7 (RGB encoder); X1 (21 MHz oscillator); U8 (CIC) |
| Scrambled video | 62-pin connector; poor solder; U3 (PPU2); U1 (CPU); U2 (PPU1); U4 or U5 (256K SRAM) |
| Distorted or no sound | Sound module; connector P5; U1 (CPU); U10 (amplifier); Q18 |
| No reset (the system reset line) | U8 (CIC); X2 (4 MHz oscillator); U9 (74HCU04) |
| Poor or no colour | TC1 (master clock adjustment); U3 (PPU2); U7 (RGB encoder); X1 (21 MHz oscillator) |
| No power | F1 (1.5 A fuse); D1; T1 (line filter); U12 (7805); VA1 (surge absorber); Q18; P3 (power switch) |
| Snowy screen | RF modulator |
| Intermittent or no controller operation | Front unit board; FFC harness; connector P2; U1 (CPU) |
| Frozen screen or erratic program | 62-pin connector; poor solder; U1 (CPU); U3 (PPU2); U2 (PPU1) |
| Ejector does not eject properly | Early ejector; replace only if the customer complains |
Not every board has D1, T1, VA1 and Q18: some were deleted during production.[6]
TC1 and the master clock
[edit | edit source]TC1 is a trimmer capacitor that sets the master clock. Playtronic's manual, written for Brazilian PAL-M consoles, sets it to 21.453666 MHz, and for a monochrome picture tells the technician to check the frequency first and, if it cannot be set or will not hold, to replace TC1 and then X1.[2] A Japanese or North American console runs at 21.47727 MHz; a European SNES has a 17.734475 MHz crystal from which the S-CLK chip makes a 21.28137 MHz master clock.[4][5] Use the figure for the console in front of you.
Colour faults
[edit | edit source]Nintendo's colour-fault notes (Playtronic p. 2-26):[2]
- Monochrome picture: check the master clock frequency at TC1; replace TC1, then X1.
- Only the RF output is wrong: replace the RF modulator.
- RF and the direct outputs both wrong: inspect the parts round the RGB encoder (U7) for solder faults and damage, then replace U7, then PPU2 (U3).
- Colour cast (reddish, bluish) on RGB, S-Video and composite: PPU2, or a missing red, green or blue signal. Check round the RGB output transistors Q3 to Q9, then replace PPU2.
- Only the RGB picture is right: the RGB encoder or the colour filters C14 and C16. Check round U7, then replace it.
The GPM mainboard
[edit | edit source]Playtronic's manual describes the later GPM (ground plane method) board. A ground layer between the tracks and the solder mask let Nintendo delete the lower RF shield. The board is shorter, C67 and the 4 MHz oscillator were removed, the sound module circuit was built onto the mainboard, TC1 became a through-hole part, and the case and upper shield were changed to fit. The cartridge lock bar in the upper case was removed and a warning label added.[2]
That describes the Brazilian board. Japanese consoles also used SNS-CPU-GPM boards, and Console5 and Altomare list a 1000 µF 25 V C67 on them; Console5 notes it is absent from North American units.[6][7] Look at your own board.
The cartridge connector
[edit | edit source]The cartridge slot is a 62-pin connector, at the top of Nintendo's list for three faults.[2] Nintendo's Japanese price list sells it as two parts, upper and lower. The upper half is replaced with a screwdriver; the lower half, soldered to the board, needs an electric desoldering tool.[1]
Nintendo's instruction to service centres was to replace a 62-pin connector rather than clean it.[2] Without new connectors, cleaning is the practical first step:
- Clean the cartridge contacts as well as the slot.
- Use isopropyl alcohol on a lint-free swab. Do not use metal polish or an abrasive on the plating.
- Look for bent pins and for cracked joints where the connector meets the board.
The Japanese manual's cleaning advice for cartridge contacts is a cotton bud with commercial AV head-cleaning fluid.[1]
Connectors and ports
[edit | edit source]| Connector | Detail |
|---|---|
| Cartridge slot | 62 pins |
| Controller ports (×2) | 7 pins each; on a daughterboard (the front unit), joined to the mainboard by an FFC harness |
| AV Multi Out | 12 pins |
| DC input | Outer sleeve positive |
| Expansion port | Underside, 28 pins |
Sources: fullsnes for the controller and Multi Out pin counts;[4] Nintendo for the front unit and FFC harness;[1] NOA's 2002 service-centre manual for the 28-pin expansion port.[8]
When refitting the FFC harness, the unprinted side (not the blue-printed side) is the contact face, and it passes through the ferrite core under the front unit.[1]
Capacitors
[edit | edit source]The SHVC-CPU-01 board has thirteen electrolytics: C50 and C51 (47 µF) on the SHVC-SOUND module, ten surface-mount parts on the mainboard, and C67, a 1000 µF 25 V radial reservoir on the DC input.[6][7] Surface-mount electrolytics can leak under the can without showing it from above.[9] Per-revision lists are in the Super Famicom Capacitor Replacement Guide.
Signs that justify opening the console: buzzing, distorted or missing sound; unstable video or colour; random resets; residue round a capacitor or green pads.
Opening the console
[edit | edit source]Nintendo's procedure (Playtronic p. 2-14):[2]
- With the AC adapter disconnected, switch the console on to discharge C67. Nintendo's note says the capacitor is known to discharge during servicing and damage components.
- Turn the console upside down and remove the six security screws from the lower case with the larger end of the LH driver. Turn it back over and lift off the upper case.
- Remove the sound module, where fitted: two screws on its far side, then lift it straight up.
- Lift the cartridge ejector bar and remove the ejector mechanism, noting the spring position.
When reassembling, the power switch is polarised: solder the red harness wire to the + side and the black to the − side.[1] Fit the cassette cover spring so that its free end sits under the step in the upper case.[1]
Handling ICs
[edit | edit source]From Nintendo's IC handling notes:[2]
- Earth yourself with a wrist strap through a resistance of several MΩ; avoid synthetic clothing and gloves.
- Use an earthed soldering iron, and solder IC pins as quickly as possible.
- Do not reuse ICs that have been removed.
- Do not test ICs with a multimeter or signal tracer; the meter's test voltage can damage them. If you must measure resistance, use the lowest range.
- Disconnect power before fitting or removing ICs.
Cleaning
[edit | edit source]- Case: damp microfibre cloth with mild detergent. No abrasives.
- Yellowed plastic: see Retrobrite.
- Controller ports and the Multi Out: soft brush and isopropyl alcohol.
- Board: anti-static brush and compressed air; isopropyl alcohol on residue, dried before reassembly. Keep liquid away from the cartridge connector and the sound module.
Tools
[edit | edit source]- Security bit for the six case screws (Nintendo's LH driver)
- Phillips drivers
- Digital multimeter
- Temperature-controlled soldering iron, flux, desoldering braid or pump; hot air for surface-mount capacitors
- Isopropyl alcohol, anti-static brush, lint-free swabs
- Plastic spudger
See Recommended Tools.
Maintenance checklist
[edit | edit source]- Confirm the adapter is 10 V DC and centre negative before connecting it.
- Clean the cartridge and the slot when games start needing a second insertion.
- With the console open, look for leaked electrolyte and check the regulator, Multi Out and controller port joints.
- Keep the console out of direct sunlight.
Related pages
[edit | edit source]- Super Famicom Capacitor Replacement Guide
- Super Famicom Troubleshooting Guide
- Super Nintendo Entertainment System
- Super Nintendo General Maintenance
- Nintendo Super NES Technical Manual (Playtronic, Rev. 01-94)
- Nintendo Famicom Service Manual
- SNES Schematic
- Retrobrite
- Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 Nintendo, ファミコン・スーパーファミコン・ゲームボーイ サービスマニュアル (Famicom / Super Famicom / Game Boy Service Manual), dated 7 August 1992, hosted at Nintendo Famicom Service Manual. HVC p. 2 (adapter DC 10 V, 13.5 ± 1.5 V off load); SHVC pp. 11–12 (power-switch harness polarity, front unit and ferrite core, FFC harness, cassette cover spring, power circuit 13–14 V into the 7805); p. 15 (SHVC repair price list: 1.5 A SSTR fuse, 7805, upper and lower 62-pin connectors, sound module); p. 21 (repair ranks).
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Playtronic / Nintendo, Manual Técnico do Super NES, Rev. 01/94, hosted at Nintendo Super NES Technical Manual (Playtronic, Rev. 01-94). p. 1-1 (10 V DC adapter); supply section (regulated Vcc 5 V, unregulated Vs 7 V); pp. 2-6, 2-7 (parts lists); p. 2-14 (disassembly, C67 discharge, six security screws, sound module); p. 2-26 (colour faults); pp. 2-28, 2-29 (console diagnostic table); p. 2-32 (SHVC-CPU-01 component layout); p. 3-1 (GPM board); pp. 8-1, 8-2 (IC handling).
- ↑ 3.0 3.1 Famicom World, "Famicom Power Adaptor" (retrieved 2026-10-01). HVC-002 rating plate and polarity; warns against NES adapters, whose output is AC.
- ↑ 4.0 4.1 4.2 4.3 4.4 Martin Korth, fullsnes, section "SNES Power Supply": 9 V AC (PAL), converted to DC inside the console; 10 V DC 850 mA (NTSC) through a diode, about 9 V internally; 7805 for the 5 V logic supply; the unregulated supply feeds only the audio amplifier. Section "SNES Timing Oscillators": PAL crystal 17.734475 MHz and master clock 21.28137 MHz. Community reference.
- ↑ 5.0 5.1 SNES Schematic, Jonathon W. Donaldson, rev. 1.5, 2014, hosted at SNES Schematic: VCC 5 V, VS 9 V, input chain T1, F1 1.5 A, D1, VA1, C67 1000 µF 25 V, P3, U12 7805. Community redraw of the SNS-CPU-GPM and -RGB boards.
- ↑ 6.0 6.1 6.2 6.3 6.4 Console5 TechWiki, "SNES" (retrieved 2026-10-01). Chip maps and capacitor lists by board revision; transcription of Nintendo's control deck diagnostic table.
- ↑ 7.0 7.1 Altomare, snes-capacitors, GitHub. Capacitor lists from boards the author repaired, including SHVC-CPU-01 and SNS-CPU-GPM-02 under "Super Famicom (NTSC)", with sizes and the SHVC-SOUND notes.
- ↑ Nintendo of America, Authorized Service Center Manual, Rev. June 2002, chapter 6 (Super NES), p. 38. Hosted as File:Nintendo Authorized Service Center Manual June 2002.pdf.
- ↑ Bob, "Restoring A Super Nintendo", RetroRGB, 31 May 2020.