Sega CD (Model 2) Capacitor Replacement Guide
The top-loading Sega CD Model 2 was made with two different main boards, with different capacitor lists, so identify the board first. On the Funai board the electronics, including the CD servo circuits, are all on the main board; with the Sony board the drive PCB has electrolytics of its own.
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.