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Sega Saturn (Model 1) Capacitor Replacement Guide

From RetroTechCollection
Sega's circuit board diagram for the 837-11493 VA0 PAL main board. Ceramics carry C numbers; every electrolytic carries a CE number.

The early Sega Saturn main boards use surface-mount aluminium electrolytics, and they leak. This page lists them by board revision, together with the power supply and CD-ROM boards, which are separate assemblies with their own designators.

How Sega numbered the Saturn

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On the Saturn, Sega splits the capacitor designators into two series: plain C numbers for ceramic chip capacitors and CE numbers for aluminium electrolytics.[1] Sega's own circuit board diagram for the VA0 PAL board, reproduced here, shows both series side by side, and the VA13 schematics use the same convention.[2]

Two footnotes to that rule, both from Sega's own parts list: CE1, CE2 and CE4 are ceramic 1 µF chip parts fitted in CE-numbered positions, and CE32 is a 10 µF 6.3 V tantalum chip.[1] Neither is part of a normal recap.

The practical consequence: a capacitor list for this machine that gives plain C designators — C1 to C20 at one value, C21 to C30 at the next — is not describing a Saturn. On the real VA0 board C1 to C20 are 0.1 µF ceramics.[1]

Which board do you have?

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Saturn board revisions differ in more than layout, so read the silkscreen — it carries both an 837- assembly number and a 171- PCB number, for example "837-11493 IC BD SATURN MAIN VA0 PAL / 171-6963B".

The shell does not reliably tell you which board is inside. If the board in front of you is a through-hole revision, use the other page regardless of which case it came in.

Beyond the main board there are three further assemblies with their own capacitors: the power supply unit, which is a bought-in module and varies by manufacturer and by mains voltage; the CD-ROM board, which likewise came from several suppliers; and the small SH-1 board (838-10834), on which only C121 (47 µF) is fitted — C108 and C122 are empty positions.[3]

The power supply

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The Saturn is mains-powered. There is no DC adaptor: the PAL machine (model MK-80200-50) is rated AC 220–240 V, 50/60 Hz, approximately 20 W, and takes a detachable mains lead.[1] Any guide that describes a 9 V or 10 V DC input for this console is describing a different machine.

That means the power supply board carries lethal voltages and stores them. The primary-side bulk capacitor is a 22–56 µF part rated 400 V on 220–240 V units.[3] Before touching the board: unplug the lead, wait, then measure across that capacitor and discharge it through a resistor until it reads near zero. Recapping this board is entirely reasonable work — it is one of the two boards most likely to need it — but do it with the mains lead out and the bulk capacitor proved dead.

The rails it produces are given in Sega's block diagram:[1]

Rail Feeds
+9 V The CD drive, and the PLL
+5 V Everything except the SDRAM
+3.3 V The SDRAM

There is no +12 V rail.

Main board lists

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The VA0 PAL list below is the one case where a manufacturer source and a community source can be compared directly: Sega's own electrical parts list for the 837-11493 board and console5's list read off real boards agree position for position, including the PAL-specific values at CE30 and CE54.[1][3] That agreement is the reason to trust the remaining revisions, which console5 documents and Sega's hosted manual does not.

VA0 — 837-11076 (NTSC)

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Value Designators
100 µF 6.3 V CE3, CE6, CE18, CE19, CE30
10 µF 16 V CE15, CE16, CE20, CE21, CE23, CE31, CE37, CE42, CE52
4.7 µF 25 V CE22
220 µF 4 V CE24, CE25, CE26, CE27, CE28, CE29
22 µF 6.3 V CE33, CE34
47 µF 6.3 V CE35, CE49, CE50, CE53
330 µF 6.3 V CE45, CE46
1 µF 50 V CE47, CE48
Not fitted CE38

VA0 — 837-11491 / 837-11493 (PAL)

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Value Designators
100 µF 6.3 V CE3, CE6, CE18, CE19
10 µF 16 V CE15, CE16, CE20, CE21, CE23, CE31, CE37, CE42, CE52
4.7 µF 25 V CE22
220 µF 4 V CE24, CE25, CE26, CE27, CE28, CE29
220 µF 10 V (6.3 V acceptable) CE30
22 µF 6.3 V CE33, CE34
47 µF 6.3 V CE35, CE49, CE50, CE53
330 µF 6.3 V CE45, CE46
1 µF 50 V CE47, CE48
100 µF 10 V CE54 (PAL boards)
Not fitted CE38

VA0.5 — 837-11493 / 837-11076-02

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Value Designators
100 µF 6.3 V CE3, CE6, CE18, CE19
10 µF 16 V CE15, CE16, CE20, CE21, CE23, CE31, CE37, CE42, CE52
4.7 µF 25 V CE22
220 µF 4 V CE24, CE25, CE26, CE27, CE28, CE29
220 µF 10 V (6.3 V acceptable) CE30
22 µF 6.3 V CE33, CE34
47 µF 6.3 V CE35, CE49, CE50, CE53, CE55
330 µF 6.3 V CE45, CE46
1 µF 50 V CE47, CE48

VA1 — 837-11613-01 / 837-11891-01

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Value Designators
100 µF 6.3 V CE3, CE6, CE18, CE19, CE30
10 µF 16 V CE15, CE16, CE20, CE21, CE23, CE31, CE37, CE42, CE52
4.7 µF 25 V CE22
220 µF 4 V CE24, CE25, CE26, CE27, CE28, CE29
22 µF 6 V CE33, CE34
47 µF 6.3 V CE35, CE49, CE50, CE53, CE55
330 µF 6.3 V CE45
220 µF 6.3 V CE46
1 µF 50 V CE47, CE48
47 µF 16 V CE58 (PAL boards)

Note the voltage ratings. CE24 to CE29 are 4 V parts in Sega's own list — that is not a typographical error, and a higher rating in the same footprint is a safe substitution, but do not assume a "standard" 16 V value for those positions.[1]

Power supply boards, 220–240 V

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Identify yours from the label; the manufacturer and model are printed on it.[3]

Panasonic ETXSE077E1C

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Value Designators
33 µF 400 V C005
1200 µF 10 V C101, C102, C105
10 µF 50 V C103

Fujitsu KS350-1401-H025/01 (first variant)

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Value Designators
33 µF 400 V C5
4700 µF 10 V C10
2200 µF 16 V C12
330 µF 16 V C15, C16, C24
2200 µF 10 V C50
47 µF 16 V C72

Fujitsu KS350-1401-H025/01 (second variant)

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Value Designators
22 µF 400 V C2
2700 µF 6.3 V C9
1500 µF 6.3 V C10
33 µF 25 V C15

Voltek S-7195

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Value Designators
56 µF 400 V C102
47 µF 25 V C106
2200 µF 16 V C202
330 µF 16 V C203, C207, C210
2200 µF 10 V C205, C206, C209

Saturns for 100–120 V mains use a different set again — Fujitsu KS350-1401 variants, Panasonic ETXSE077J1B, Phihong PSM3507, Voltek S-7194, S-7208, S-7218 and 34288/34507/34588 series, and Yamaha XQ155, XQ468, XQ981, XR258 and XS205 — each with its own list.[3]

CD-ROM boards

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JVC EXL-P604

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Value Designators
100 µF 10 V C102
2.2 µF 50 V C117
47 µF 10 V C118, C120
220 µF 6.3 V C210
220 µF 10 V C306

JVC EXL-P605

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Value Designators
100 µF 10 V C102
47 µF 16 V C104, C119
2.2 µF 50 V C121
220 µF 6.3 V C210, C307

JVC ENR-007 B / D

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Value Designators
47 µF 10 V C101
100 µF 10 V C106, C230, C509
22 µF 16 V C202
4.7 µF 50 V C211 (rev D)
10 µF 25 V C220
220 µF 10 V C301
Not fitted C208

Hitachi JA00292

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Value Designators
22 µF 6.3 V C501, C502, C504, C506, C623, C701, C712
47 µF 16 V C511
47 µF 6.3 V C609
2.2 µF 50 V C614
10 µF 16 V C615, C626
100 µF 6.3 V C722, C724

Sanyo CDK94V5SGC

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Value Designators
100 µF 6.3 V C101, C127, C128, C150, C207
10 µF 16 V C103, C130
220 µF 6.3 V C111
330 µF 6.3 V C114
47 µF 10 V C117
0.33 µF 50 V C119
1 µF 50 V C133, C303
4.7 µF 50 V C153
22 µF 16 V C157

Doing the work

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  1. Unplug the mains lead. Remove the case screws and the top shell, then the CD compartment lid, the shield plate and the SH-1 board, then the four screws holding the CD drive unit supports and the five holding the main board. The power, power-indicator and R.SW boards come out last, on three, one and two screws respectively.[1]
  2. Lift the surface-mount electrolytics with hot air or by rocking with two irons. Saturn pads lift easily; do not lever.
  3. Wash every footprint with isopropyl alcohol and inspect under magnification. Electrolyte that has run under an adjacent part will keep corroding after the capacitor is gone — see Battery Explosion, Capacitor or Corrosion Damage.
  4. Fit 105 °C low-ESR parts at the original value, or the original value with a higher voltage rating. Stripe to the negative end.
  5. Leave the trimmers on the CD board alone. They are servo adjustments and setting them needs an oscilloscope and a test disc.[1]

General tooling is on Recommended Tools; the symptom-by-symptom picture is on Capacitor Failure Symptoms.

After the recap

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  • Check +5 V, +9 V and +3.3 V at the power connector on the main board.[1]
  • With a disc loaded and playing, the RF eye pattern at the RF test point should be 0.8 to 1.4 Vp-p. Below 0.8 Vp-p, Sega's instruction is to replace the pickup.[1]
  • A machine that boots, plays an audio CD and runs a game from disc has exercised almost everything the electrolytics sit in.
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References

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  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Sega Enterprises, Ltd., Service Manual — Sega Saturn (PAL), No. 013-1, June 1995 — hosted on this wiki as File:Sega service manual - sega saturn pal - no. 013-1 june 1995.pdf (see Sega Service Manual - Sega Saturn Pal - 1 June 1995). Section 1 gives the ratings, section 5 the disassembly, section 6 the CD drive maintenance and adjustment figures, section 7 the block diagram with the power supply rails, section 9 the circuit board diagrams and section 11-3 the electrical parts list for the VA0 main board.
  2. Sega Saturn VA13 Service Manual (PAL) — hosted on this wiki as File:Sega Saturn VA13 Service Manual PAL.pdf (see Sega Saturn VA13 Service Manual (PAL)). A partial scan: block diagram, power supply and CD unit sheets and eleven main-board schematic sheets. It carries no parts list, but its schematics use the same C / CE designator split as the VA0 manual.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 console5 TechWiki, Saturn, https://wiki.console5.com/wiki/Sega_Saturn . Secondary source — per-revision capacitor lists read off real boards, covering VA0 through VA15, the power supply units by manufacturer and model, and the CD-ROM PCBs. Its VA0 PAL list (837-11491 / 837-11493) agrees position for position with the parts list in Sega’s own PAL service manual, including the values at CE30 and CE54 that are specific to PAL boards.