Sega Dreamcast Capacitor Replacement Guide

A Sega Dreamcast holds its electrolytics in four places: the logic board, the power supply, the GD-ROM optical board and the small controller-interface board. All four have their own designators, all four vary by revision, and none of them is interchangeable with another.

No Sega Dreamcast service manual carrying a parts list is hosted on this wiki — the Sega Dreamcast VA0 Schematics here are schematics and diagrams only, with no bill of materials. Every value on this page therefore comes from console5's board-reads, and is cited as the secondary source it is.^[1]

How the Dreamcast is numbered

On the logic board, aluminium electrolytics carry CE designators — CE103, CE301 to CE310, CE401, CE403, CE503, CE601, and the CE7xx and CE8xx positions on later boards.^[1] Plain C numbers on a Dreamcast belong to the GD-ROM board or the power supply, which use their own sequences.

A logic-board capacitor list built out of consecutive plain C designators is therefore not describing this machine, whatever the values say.

Identify the board

Revision	Notes
VA0	Earliest logic board. No CE103, CE302, CE307 or CE601 fitted
VA1	837-13778 / 171-7965C. The most common board
VA2.1	Adds the CE7xx and CE8xx positions and drops CE503

All Dreamcast consoles have an internal, mains-powered supply. There is no revision that takes an external power brick: console5 lists internal supply boards for both 110 V markets (171-7874A, -7874A-X1, -7874B, -7874B-X2, 171-7962A, -7962A-X1, 171-7970A, -7970A-X2) and 220–240 V markets (171-7960A, PWR UNIT PANA EU V01, ETXSE239E2C).^[1] Any guide that says a Dreamcast revision uses an external PSU and needs no internal supply work is wrong, and following it would leave the most failure-prone board in the machine untouched.

Logic boards

VA0 logic board^[1]
Value	Designators
10 µF 16 V	CE301, CE310
10 µF 10 V, bipolar	CE303, CE304
22 µF 6.3 V	CE305, CE306
47 µF 16 V	CE308
4.7 µF 35 V (25 V acceptable)	CE309
220 µF 6.3 V	CE401
100 µF 6.3 V	CE403
47 µF 25 V	CE503

VA1 logic board, 837-13778^[1]
Value	Designators
47 µF 16 V	CE103, CE308
10 µF 16 V	CE301, CE302, CE310
10 µF 10 V, bipolar	CE303, CE304
22 µF 6.3 V	CE305, CE306
100 µF 16 V	CE307
4.7 µF 35 V (25 V acceptable)	CE309
220 µF 6.3 V	CE401
100 µF 6.3 V	CE403
47 µF 25 V	CE503
47 µF 6.3 V	CE601

VA2.1 logic board^[1]
Value	Designators
47 µF 16 V	CE103, CE308
10 µF 16 V	CE301, CE302, CE310
10 µF 10 V, bipolar	CE303, CE304
22 µF 6.3 V	CE305, CE306
100 µF 16 V	CE307, CE801, CE802, CE805, CE808
4.7 µF 35 V (25 V acceptable)	CE309
220 µF 6.3 V	CE401
100 µF 6.3 V	CE403, CE701, CE807
47 µF 6.3 V	CE601, CE803, CE804, CE806
47 µF 25 V	CE809

CE303 and CE304 are bipolar parts. They are non-polarised by design and must be replaced with bipolar capacitors, not with ordinary polarised electrolytics fitted "the right way round".^[1]

The controller-interface and battery board carries one capacitor, CE1, 47 µF 16 V, on every revision.^[1]

GD-ROM optical boards

GD-ROM boards^[1]
Board	Value	Designators
XU937	47 µF 6.3 V	C2
	100 µF 6.3 V	C3, C10, C14, C17, C61
	100 µF 16 V	C20, C122
XV779 / KS-7S	100 µF 6.3 V	C10, C14, C17, C61, C511
	100 µF 16 V	C20, C509
	47 µF 6.3 V	C127, C203, C205
171-8129A	100 µF 6.3 V	C10, C14, C17, C61, C513, C520
	100 µF 16 V	C20, C509
	47 µF 6.3 V	C127, C203, C205

On the XV779 board, C510 is an empty position.^[1]

The other common GD-ROM fault is mechanical rather than electrical: the plastic spur gears in the optical drive strip, which stops the sled moving. console5 hosts an installation guide for replacement gears.^[1] A drive that spins a disc but never reads it is worth checking for a stripped gear before the laser is condemned.

Power supplies

The supply board is the one board in a Dreamcast that carries mains potential, and its bulk capacitor stores charge after the lead is pulled: 100 µF at 200 V on 110 V units, 47 µF at 400 V on 220–240 V units.^[1] Unplug the console, measure across that capacitor and discharge it through a resistor before working. Done that way this is ordinary repair work, and on a machine of this age the supply is usually the board most in need of it.

Power supply boards^[1]
Board	Value	Designators
171-7874A, -7874A-X1, -7874B (110 V; usually paired with VA0)	100 µF 200 V	C3
	47 µF 35 V	C10
	1000 µF 25 V	C13
	220 µF 25 V	C16
	2200 µF 10 V	C17, C21
	1500 µF 6.3 V / 470 µF 10 V	C20 / C22
171-7874B-X2, 171-7962A, -7962A-X1, 171-7970A, -7970A-X2 (110 V; usually VA1 and VA2.1)	100 µF 200 V	C3
	47 µF 35 V	C10
	470 µF 35 V	C52
	470 µF 16 V	C53
	2200 µF 10 V	C54
	470 µF 10 V	C56
	3300 µF 10 V / 1000 µF 10 V	C58 / C59
171-7960A, PWR UNIT PANA EU V01, ETXSE239E2C (220–240 V)	47 µF 400 V	C006
	1800 µF 16 V	C101, C201
	1200 µF 10 V	C103
	470 µF 16 V	C204
	1000 µF 25 V (35 V on some units)	C301, C302

The switching controller on the supply is an FA5317.^[1]

IC map, VA1 171-7965C

Useful when tracing a rail back to what it feeds.^[1]

Designator	Device	Function
IC101	SH-4	Main CPU
IC102, IC103	64 Mbit SDRAM	Main memory
IC104	PQ07VZ1H2Z	Series regulator
IC106	RN5RG25A	CMOS regulator — the fitted part is tied to the Holly variant: 313-5612 with a 315-6201 or 315-6225, 313-5553 with a 315-6226
IC201	315-6201 / 315-6225 / 315-6226	Holly graphics engine
IC202–IC205	16 Mbit SDRAM	Video memory
IC206	RN5VD27A	Power-on reset
IC301	315-6119 / 315-6232	AICA sound processor
IC302	16 Mbit SDRAM	Sound memory
IC303	PCM1725	Audio DAC
IC305	W129A	Clock generator
IC401	BU1426KS	RGB encoder
IC501	MPR-21931	Boot ROM

Doing the work

Unplug the console. Remove the modem, then the case screws, then the top shell.
Take the power supply out and discharge its bulk capacitor before anything else.
Note the orientation of every connector before unplugging it.
Lift the surface-mount parts on the logic board with hot air or two irons, never by levering.
Clean each footprint with isopropyl alcohol and inspect under magnification — see Battery Explosion, Capacitor or Corrosion Damage if anything has leaked.
Fit 105 °C low-ESR parts at the original values, bipolar where the original was bipolar, stripe to the negative end.
Reassemble and test before closing the case.

General tooling is on Recommended Tools; what each failure mode looks like is on Capacitor Failure Symptoms.

After the recap

This wiki has not found a source that publishes the Dreamcast's rail voltages and tolerances — Sega's hosted schematics do not tabulate them — so no voltage table is given here rather than a guessed one. What can be checked without one:

the console powers up and reaches the boot animation with no disc;
audio is clean on both channels, which exercises the AICA, the PCM1725 and the capacitors around them;
video is stable and free of noise;
the GD-ROM spins up, the sled moves smoothly and a game disc loads;
the machine still works after twenty minutes warm, which is when a marginal supply shows itself.

Related pages

References

↑ ^1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 ^1.10 ^1.11 ^1.12 ^1.13 ^1.14 console5 TechWiki, Dreamcast, https://wiki.console5.com/wiki/Dreamcast . Secondary source — capacitor lists read off real boards for the VA0, VA1 and VA2.1 logic boards, the GD-ROM optical boards, the controller interface board and the power supply units, together with the IC map for the VA1 171-7965C board. No Sega Dreamcast service manual with a parts list is hosted on this wiki, so this is the only component-level source cited here.

[c5dc-1] 1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 ^1.10 ^1.11 ^1.12 ^1.13 ^1.14 console5 TechWiki, Dreamcast, https://wiki.console5.com/wiki/Dreamcast . Secondary source — capacitor lists read off real boards for the VA0, VA1 and VA2.1 logic boards, the GD-ROM optical boards, the controller interface board and the power supply units, together with the IC map for the VA1 171-7965C board. No Sega Dreamcast service manual with a parts list is hosted on this wiki, so this is the only component-level source cited here.

[1]