Amstrad PC3286 Capacitor Replacement Guide
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The Amstrad PC3286 has electrolytic capacitors in its power supply, on the main board it shares with the Amstrad PC3386SX, and on the plug-in 286 processor board. Amstrad's service manual for the Generation 3 range (reference SM-PC3000, 53 pages with full schematic and wiring diagrams) has not been published online; the Centre for Computing History holds a copy as exhibit CH27476. No capacitor values for any PC3286 board have been published.[1][2]
The case, the supply, the safety notes and the general method are the same as on the Amstrad PC3086 and are set out in the Amstrad PC3086 Capacitor Replacement Guide.
What is inside
[edit | edit source]| Assembly | Detail | Source |
|---|---|---|
| Power supply | A closed metal unit at the back of the case, rated 145 W in Amstrad PC International's specification table. Its wiring loom is stiff and gets in the way of cards in the two upright slots | Amstrad PC International[2] |
| Main board | The same board as the PC3386SX, with the processor on a plug-in card. Four SIMM sockets, the clock module, the VGA and the IDE interface are on this board | Amstrad PC International;[2] user manual[3] |
| Processor board | MS0188A, marked "Amstrad Z70922 copyright 1990". It carries the 80286 (IC701) and the empty 80287 socket (IC700) | Centre for Computing History photograph;[4] tarasque's photographs;[5] user manual[6] |
| Expansion card for the horizontal slots | Two 16-bit and one 8-bit full-length slots sit on a card plugged into a 16-bit slot on the main board | Amstrad PC International[2] |
Known electrolytic positions
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The 286 processor board has one electrolytic, C704, an axial part lying along the bottom edge next to PL701. The side of its sleeve facing the camera shows "25" and "85 °C"; the capacitance is printed on the side that cannot be seen. The other capacitors on the board, C701, C703, C705 and C709, are small dipped parts, and C707 is a flat rectangular part beside PL702.[4]
In tarasque's photographs of the main board most capacitors are small surface-mount and dipped parts. One small radial electrolytic in a blue sleeve stands near the rear connectors, just below the processor board; its markings cannot be read at the size of the photograph.[5] That machine had already had its clock module replaced with a modern equivalent.[5]
Recording the PC3286 boards
[edit | edit source]Record three boards: the supply, the main board and the processor board. Note the board numbers (MS0188A on the 286 processor board) so that a PC3386SX owner can compare main boards with yours. Amstrad's manual gives one main board drawing for both models, and Amstrad PC International concluded from its test machine that only the processor card differs.[7][2][5] For each electrolytic, write down the designator, capacitance, voltage, temperature rating, size and polarity, read from the part itself. See the PC3086 guide for the full method.
Procedure
[edit | edit source]- Unplug the mains lead and the monitor's power lead, and open the case as for the PC3086: slide the lid forwards by about 75 mm only, because the front panel is wired to the main board.[6]
- Label and unplug the supply's leads. The loom is stiff, so move it aside by hand once the plugs are free.[2]
- Remove the processor board from the main board as shown on p. 7-5 of the user manual before working on the area underneath it, and refit it the same way round afterwards.[6]
- Replace the electrolytics one at a time with parts of the same capacitance, the same or a higher voltage rating, and the same polarity.
- Refit the processor board and any SIMMs you removed, check that the SIMMs are seated, and close the case.
After the recap
[edit | edit source]At switch-on the PC3286 prints "Please wait." with a dot after each test, then "AMSTRAD PC3286 (V2.0)" and the base memory.[8] If the processor board was taken out and the machine then fails to start, check first that the board is fully seated. The error messages are in the Amstrad PC3286 Troubleshooting Guide, and the full message tables in the Amstrad PC3086 Troubleshooting Guide.
Related pages
[edit | edit source]- Amstrad PC3286 · Amstrad PC3286 Maintenance Guide · Amstrad PC3286 Troubleshooting Guide
- Amstrad PC3086 Capacitor Replacement Guide · Amstrad PC3386SX Capacitor Replacement Guide
- Capacitor Failure Symptoms · Recommended Tools
References
[edit | edit source]- ↑ Centre for Computing History, "Amstrad PC3086 PC3286 PC3386SX Colour Personal Computers Service Manual" (CH27476): 53-page service manual with full schematic diagrams and wiring diagrams, reference SM-PC3000, published 1990. Retrieved 2026-10-21.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Thomas Kallay, test of the Amstrad PC3286, Amstrad PC International, December 1990/January 1991, pp. 50–51. Internet Archive. Retrieved 2026-10-21. Specification table (AMD 80286 at 16 MHz, 145 W supply), the main board shared by the 3286 and 3386 with a processor card on top, the three horizontal slots on a plug-in card in a 16-bit slot, the stiff wiring loom from the supply crowding the two upright slots, criticism of the 145 W rating, and photographs of the back panel (Bild 1) and the interior (Bild 2).
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 8-6 to 8-10. Memory cache, the four SIMM sockets and the memory size and DRAM speed links.
- ↑ 4.0 4.1 Centre for Computing History, "Amstrad PC3286 286 Daughterboard" (CH42246), 1990, with a photograph of the component side, hosted here as File:Amstrad PC3286 processor board MS0188A (Centre for Computing History).jpg. Retrieved 2026-10-21.
- ↑ 5.0 5.1 5.2 5.3 Vogons forum, "Amstrad 3286", tarasque and others, September 2024 to February 2025. Photographs of a PC3286 main board and processor board (CC BY 4.0), hosted here as File:Amstrad PC3286 main board.jpg and File:Amstrad PC3286 processor board MS0188A.jpg. Viewed on the wiki 2026-10-21.
- ↑ 6.0 6.1 6.2 Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 7-2 to 7-6. The co-processor socket on the PC3286 and PC3386SX daughterboard, opening the system unit, and removing the daughterboard (p. 7-5 for the PC3286).
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 11-1 to 11-10. Expansion slots, opening the lid, and the option links; p. 11-7 draws one main board for "both models", the PC3286 and PC3386SX.
- ↑ Amstrad plc, User Manual and MS-DOS Guide for the PC3086, PC3286 and PC3386SX, 2nd ed. (1990), pp. 3-7 to 3-9. The voltage selector, the "Please wait." self-test dots and the PC3286 and PC3386SX start-up message.
