Sega Saturn (Model 2) Capacitor Replacement Guide
Recapping a Sega Saturn (Model 2) is crucial for restoring stable video, audio, and power delivery. Ageing electrolytic capacitors in these mid-1990s consoles can cause audio distortion, video artefacts, random resets, and even permanent board damage from leakage. Proactive replacement ensures reliable operation and preserves your Saturn for years to come.
Visual Inspection & Failure Signs
[edit | edit source]Before beginning, carefully inspect the mainboard and power supply for:
- Bulging or domed capacitor tops – Indicates internal pressure and imminent failure.
- Leaking electrolyte – Brown or greenish residue around capacitor bases, especially near the audio and power sections.
- Corrosion or PCB staining – Green or blackened areas signal leakage and possible trace damage.
- Audio or video issues – Buzzing, hissing, or rolling video may trace to dried-out SMD capacitors.
- Random resets or failure to boot – High ESR in power rail capacitors can cause instability.
If any capacitor shows trouble, replace all electrolytic capacitors on the board.
Sega Saturn Model 2 Capacitor List
[edit | edit source]The Saturn Model 2 (VA0, VA1, VA2, etc.) uses a mix of through-hole and SMD electrolytic capacitors. Values and locations may vary slightly by region and board revision—always cross-check your silkscreen and part markings.
Mainboard Electrolytic Capacitors
[edit | edit source]| Ref. Designator | Capacitance | Voltage | Type | Location / Function |
|---|---|---|---|---|
| C1, C2, C3, C4, C5, C6, C7, C8, C9, C10 | 10 µF | 16 V | SMD | Audio, video, RAM decoupling |
| C11, C12, C13, C14, C15, C16 | 22 µF | 16 V | SMD | Audio path, DAC filtering |
| C17, C18, C19 | 47 µF | 16 V | SMD | Power rail smoothing |
| C20, C21, C22 | 100 µF | 10 V | SMD | Audio amp, video encoder |
| C23, C24 | 220 µF | 10 V | SMD | Audio output, 5 V rail |
| C25 | 470 µF | 10 V | SMD | Main 5 V decoupling |
| C26 | 1000 µF | 10 V | Through-hole | Main 5 V bulk filter (near power input) |
Some board revisions may use 6.3 V or 25 V rated capacitors for certain positions. Always match or exceed the original voltage rating.
Power Supply Board (Internal PSU)
[edit | edit source]| Ref. Designator | Capacitance | Voltage | Type | Notes |
|---|---|---|---|---|
| C101 | 220 µF | 200 V | Through-hole | Mains filter (primary side) |
| C102 | 1000 µF | 16 V | Through-hole | 5 V rail output filter |
| C103 | 470 µF | 16 V | Through-hole | 9 V rail output filter |
| C104 | 47 µF | 50 V | Through-hole | Standby/auxiliary rail |
Some Saturns use an external PSU (“Type B”); if so, only the mainboard needs recapping.
Recapping Procedure
[edit | edit source]- Disassemble the Saturn: Remove the screws from the case bottom, gently separate the top shell, and unplug the power supply and drive cables.
- Remove the mainboard: Take out all screws securing the mainboard. Disconnect controller ports and ribbon cables.
- Label connectors and take photos to aid reassembly.
- Desolder each capacitor: Use a soldering iron (350–375 °C) and desoldering braid or pump. For SMD capacitors, gently heat both sides and lift with tweezers.
- Clean pads thoroughly: Remove all old flux and leaked electrolyte with isopropyl alcohol and a brush.
- Install new capacitors: Match polarity (long lead = positive for through-hole; SMD stripe = negative). Use low-ESR, 105 °C rated capacitors. For SMD, bend radial leads flat if necessary.
- Inspect for solder bridges and clean the board again.
- Reassemble and test before fully closing the case.
Recommended Tools & Parts
[edit | edit source]- Temperature-controlled soldering iron (fine tip, 2 mm chisel for through-hole, conical for SMD)
- Desoldering braid and/or spring pump
- Tweezers for SMD removal
- Isopropyl alcohol (99%) and antistatic brush
- Multimeter (for continuity and voltage checks)
- High-quality 105 °C, low-ESR capacitors (Nichicon, Panasonic, Rubycon)
- Kapton tape (to insulate capacitors near shielding)
- ESD mat and wrist strap
Post-Recap Voltage & Ripple Checks
[edit | edit source]After reassembly, verify the main voltage rails at the power supply output or mainboard test points:
| Test Point | Expected Voltage | Max Ripple (p-p) |
|---|---|---|
| 5 V rail (mainboard input) | 4.90 – 5.10 V | < 40 mV |
| 9 V rail (if present) | 8.7 – 9.3 V | < 80 mV |
| Audio amp Vcc | 4.8 – 5.1 V | < 40 mV |
Excessive ripple or unstable voltage may indicate a missed or incorrectly installed capacitor.
Extra Tips
[edit | edit source]- Always match polarity! SMD caps have a stripe for negative; through-hole, the long lead is positive.
- Clean up any leaked electrolyte thoroughly—residue is corrosive and conductive.
- Replace all electrolytics at once—partial recaps are unreliable.
- Use slightly higher voltage ratings if space allows, but do not exceed original capacitance by more than 20%.
- If you hear buzzing or see video artefacts after recap, double-check for solder bridges or reversed capacitors.
- Dispose of old capacitors responsibly at an electronics recycling centre.