Sega CD (Model 2) Capacitor Replacement Guide
The top-loading Sega CD Model 2 has its electronics, including the CD servo circuits, on one main board, so a recap is a single-board job. Two different main boards were made, with different capacitor lists, so identify the board first.
Identify the board
[edit | edit source]| Board | How to tell | Source for its list |
|---|---|---|
| "Funai" board: Sega 837-9615 (Sega CD II, USA) or 837-9616 (Mega CD II, multi); later 837-10210, -10211, -10213, -10214 | Silkscreened BE2200G02 with a revision suffix: A02, B02, C02 or C22[1] | Sega's parts lists for A02, B02 and C02;[2] Console5 for C22 |
| "Sony" board, 171-6528C | Boot ROM MPR-15764-T at IC111[3] | Console5 only; Sega's manuals do not cover this board |
On the Funai board, units from serial number T30282001 have larger chip parts (2.0 × 1.25 mm instead of 1.6 × 0.8 mm), a changed board pattern, IC001 and IC002 renumbered IC951 and IC952, and no PCM board 837-9798.[4]
How the board is numbered
[edit | edit source]Sega numbers the capacitors in one C series, in blocks of hundreds by circuit area, with ceramics and electrolytics mixed in each block. There is no separate CE series. C138 is a 0.1 µF ceramic and C139 next to it a 10 µF electrolytic; C302 is a 0.1 µF ceramic between the electrolytics C301 and C303.[2] Sega's part number shows the type: 150-xxxx is an electrolytic and 151-xxxx a ceramic.
Visual inspection
[edit | edit source]Look for brown or green residue around a capacitor, stained solder resist, a domed top, or corroded or lifted pads. Capacitor Failure Symptoms explains each sign, and Battery Explosion, Capacitor or Corrosion Damage covers cleaning up after a leak.
Funai board: BE2200G02A02, -B02 and -C02
[edit | edit source]Sega's parts lists and Console5's board read agree on this board.[2][4][1]
| Value | Sega part | Designators |
|---|---|---|
| 10 µF 16 V | 150-0439 | C104, C110, C115, C122, C127, C129, C131, C132, C139, C206, C207, C208, C209, C210, C220, C221, C222, C228, C229, C232, C233, C234, C235, C236, C237, C239, C240 |
| 100 µF 6.3 V | 150-0440 | C201, C238, C301, C306, C404, C408, C409, C903 |
| 1000 µF 6.3 V | 150-0441 | C303, C450 |
| 330 µF 16 V | 150-0249 | C305, C403 |
| 470 µF 6.3 V | 150-0301 | C406 |
| 22 µF 6.3 V | 150-0443 | C411, C412 (see below) |
| 3.3 µF 50 V | 150-0329 | C407 |
| 1 µF 50 V | 150-0016 | C413, C455 |
| 0.47 µF 50 V | 150-0442 | C410, C414 |
That is 47 electrolytics. C412 depends on the drive unit: Sega's supplement gives 22 µF 6.3 V with drive 610-5608 (labelled KSS-210A) and 47 µF 6.3 V (150-0467) with drive 610-5603 (labelled SOHOT4).[4] Console5 lists 22 µF 10 V for the first; a higher voltage rating of the same value is a safe substitute.[1]
Funai board: BE2200G02C22
[edit | edit source]Console5's list for the later C22 board differs.[1]
| Value | Designators |
|---|---|
| 10 µF 16 V | C104, C110, C115, C122, C127, C131, C132, C139, C206, C207, C208, C209, C210, C221, C222, C228, C229, C236, C237, CC241, C242, C941 |
| 100 µF 6.3 V | C201, C238, C306, C404, C408, C409, C903 |
| 1000 µF 6.3 V | C303, C450 |
| 330 µF 16 V | C305, C403 |
| 470 µF 6.3 V | C406 |
| 22 µF 16 V | C411, C412 |
| 47 µF 10 V | C456 |
| 3.3 µF 50 V | C407 |
| 1 µF 50 V | C413, C455 |
| 0.47 µF 50 V | C410, C414 |
| Not fitted | C301, C405 |
The silkscreen on this board reads CC241 for C241.[1]
Sony board: 171-6528C
[edit | edit source]The 10 µF capacitors on this board are 50 V parts.[3]
| Value | Designators |
|---|---|
| 10 µF 50 V | C104, C107, C110, C115, C122, C127, C129, C131, C132, C139, C206, C207, C208, C209, C210, C220, C221, C222, C228, C229, C232, C233, C234, C235, C236, C237, C239, C240, C413 |
| 100 µF 6.3 V | C201, C238, C301, C306, C401 |
| 1000 µF 6.3 V | C303 |
| 330 µF 16 V | C305 |
| 0.47 µF 50 V | C400 |
The drive units used with this board have their own electrolytics:[3]
| Drive | Designator | Value |
|---|---|---|
| KSK-1310A (KSM2401AAN mechanism, KSS-240A pickup) | C103 | 4.7 µF 50 V |
| C105, C106 | 47 µF 10 V | |
| C107 | 10 µF 50 V | |
| C111 | 22 µF 25 V | |
| C156 | 330 µF 16 V | |
| Optima 6S | C501, C507, C581 | 47 µF 6.3 V |
| C508, C551 | 100 µF 16 V | |
| C510 | 1 µF 50 V | |
| C543, C546 | 10 µF 16 V | |
| C548 | 100 µF 6.3 V |
Procedure
[edit | edit source]- Unplug the adaptor and separate the unit from the console.
- Turn the unit over and remove six screws from the bottom. Turn it the right way up again before lifting off the top case; Sega says not to remove the bottom case with the unit upside down.[5]
- Remove the five screws holding the shield plate, disconnect the three connectors from the CD drive unit, and remove the two screws holding the circuit board assembly.[5]
- Remove the surface-mount capacitors with hot air or two irons. Do not twist or lever them off.
- Clean each footprint with isopropyl alcohol and inspect for corroded tracks before fitting the new part.
- Fit 105 °C parts of the same value and at least the same voltage rating, observing polarity.
General tools are listed on Recommended Tools.
After the recap
[edit | edit source]Sega's servicing flowcharts give these checks:[6]
- 9 V at IC409 pins 1, 12 and 13, and 5 V at IC403 pins 10 and 37. If they are missing, check the power circuit.
- Setting the door switch SW401 from off to on lights the laser for about two seconds and moves the lens up and down.
- An RF waveform of about 1.5 Vp-p at IC402 pin 2 (TP-RF) while a disc plays; laser power 90 to 120 µW.
Leave VR401, VR402 and VR403 alone during a recap. They are the EF balance, tracking gain and VCO adjustments, and Sega's procedure for them needs its adjustment jig, a Sony TYPE-4 test disc, a frequency counter, an oscilloscope, an audio generator and two voltmeters.[7]
Related pages
[edit | edit source]- Sega CD (Model 2)
- Sega CD (Model 2) Maintenance Guide
- Sega CD (Model 2) Troubleshooting Guide
- Sega CD (Model 1) Capacitor Replacement Guide
- Capacitor Failure Symptoms
- Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Sega CD v2: Funai—link(accessed 2026-10-01) Secondary source; capacitor lists read off real boards. Its A02/B02/C02 list agrees position for position with Sega's parts list.
- ↑ 2.0 2.1 2.2 Sega Enterprises, Ltd., Service Manual, Sega CD II / Mega CD II, No. 002, August 1993, section 13-3, electrical parts list, pp. 39-42. See Sega CD 2 / Mega CD 2 - Service Manual.
- ↑ 3.0 3.1 3.2 3.3 3.4 Sega CD v2: Sony—link(accessed 2026-10-01) Secondary source; capacitor lists read off real boards.
- ↑ 4.0 4.1 4.2 Sega Enterprises, Ltd., Service Manual Supplement, Sega CD II / Mega CD II, No. 002-2, June 1994, pp. 2 (difference table) and 12-16 (electrical parts list). See Sega CD 2 / Mega CD 2 - Service Manual Supplement.
- ↑ 5.0 5.1 Sega Enterprises, Ltd., Service Manual, Sega CD II / Mega CD II, No. 002, August 1993, section 3, disassembly, pp. 4-5. See Sega CD 2 / Mega CD 2 - Service Manual.
- ↑ Sega Enterprises, Ltd., Service Manual, Sega CD II / Mega CD II, No. 002, August 1993, section 8, guides for servicing, pp. 11-14. See Sega CD 2 / Mega CD 2 - Service Manual.
- ↑ Sega Enterprises, Ltd., Service Manual, Sega CD II / Mega CD II, No. 002, August 1993, section 4, CD drive adjustment, pp. 6-7. See Sega CD 2 / Mega CD 2 - Service Manual.