Amstrad PC2386 Maintenance Guide
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The Amstrad PC2386 has its power supply in the system unit, with its own fan. Amstrad's service manual allows component-level repair of the supply and monitors but treats the main CPU board and the drives as exchange items, and gives an alignment procedure for the supply, the video clock and the real-time clock.[1] The Amstrad PC2086 Maintenance Guide covers the smaller PC2086 of the same series.
Safety
[edit | edit source]Warning: the supply runs from the mains; its reservoir capacitor C601 (330 µF 400 V) holds a dangerous charge after unplugging.
- Unplug the machine and discharge C601 before working on the supply board.[1]
- After servicing, Amstrad's safety tests are a 1.5 kV RMS flash test for 3 s, an insulation resistance of more than 4 MΩ and mains-lead earth continuity of no more than 0.5 Ω.[1]
- See CRT Discharge Procedure before opening a monitor.
Alignment
[edit | edit source]| Step | Method |
|---|---|
| +5 V | Voltmeter at test point A; set VR604 to 5.00 V ±0.05 V |
| +12 V | Voltmeter at test point B; set VR603 to 12.00 V ±0.05 V |
| VCO control voltage | Voltmeter at pin 6 of IC316; set TC301 to 3.5 V |
| Primary protection | Turn VR601 anticlockwise until the protection starts to cut in, then back a little |
| Real-time clock | Timing meter at pin 21 of IC115, set to 0.2 s/day; set TC101 to read 0.00 |
The alignment has no step for −5 V or −12 V; the supply's parts list includes AN7905F and AN7912T fixed negative regulators at IC606 and IC607.[1] Measure all four rails with the main board connected.
Supply fan
[edit | edit source]The supply has a fan, M601.[1] On the closely related PC2286 supply, an owner found the fan was a 60 × 25 mm 12 V unit and fitted a quieter replacement.[2] Check the label on yours before ordering.
Backup cells
[edit | edit source]The PC2000 series keeps its BIOS settings in clock memory backed by four AA cells in the top of the base unit, under the monitor.[3][4] Remove old cells and clean any leakage; see Battery Explosion, Capacitor or Corrosion Damage. With fresh cells, re-enter the BIOS settings, including the hard disc type; one owner rebooted from the original 65 MB drive after setting the BIOS again.[5]
Drives
[edit | edit source]Amstrad's parts list gives the floppy drive as an OSDA-45A and the hard disc as a Seagate ST277R.[1] One owner's machine has a Citizen OSDA-46 floppy drive on a straight cable, set to drive ID 0; drives from other machines set to ID 0 did not work in it, although the Amstrad drive worked in another computer.[6] Keep the original drive if it works; see Floppy Drive Repair. The same owner noticed an unused IDE connector on the main board.[7] See Hard Drive Maintenance and Repair for the hard disc.
Keyboard
[edit | edit source]The keyboard uses Amstrad's own protocol on a 5-pin DIN socket of the 270-degree type, so neither an AT nor an XT keyboard will plug in. Owners identify the PC2386 keyboard by the "PC2386" marking on top and type 7220000503 on the label, with an MK0006A controller board inside.[7]
To clean a keyboard that gives a keyboard error:[7]
- Open the keyboard. It has no screws, only clips, and the old plastic is brittle; work slowly.
- Clean the edge connectors of the two membrane sheets where they meet the controller board.
- Separate the two membrane layers. One owner found that layers squeezed together held a key down, and the keyboard worked again after they were separated and refitted.
Memory
[edit | edit source]One owner swapped the machine's SIMMs for another matched set of four while chasing a fault.[5] The PC2286 of the same series also takes SIMMs, with jumpers to set; see the Amstrad PC2286 Maintenance Guide.
Related pages
[edit | edit source]- Amstrad PC2386 · Amstrad PC2386 Troubleshooting Guide · Amstrad PC2386 Capacitor Replacement Guide
- Amstrad PC2086 Maintenance Guide · Amstrad PC2286 Maintenance Guide
- Amstrad PC 2386 Service Manual · Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Amstrad plc, PC2386-65 Personal Computer Service Manual. Hosted as File:Amstrad PC 2386 Service Manual.pdf, described at Amstrad PC 2386 Service Manual. Specification, notes to engineers and safety tests p. 2; alignment instructions p. 3; main PCB views pp. 4–5; electrical parts list pp. 44–45. The cabinet parts list (p. 47) and power supply schematic (p. 48) are hosted separately as File:Amstrad PC 2386 Service Manual pages 47-48.pdf.
- ↑ VintageVic, acgs, GiGaBiTe and others, "Amstrad PC 2286", Vintage Computer Federation Forums, April 2022 – October 2022. Retrieved 2026-10-02. Community repair of a PC2286 supply: the parts list of its supply ICs and electrolytics, the 60 × 25 mm 12 V fan, the main board power connector pinout, and the two-board main board/expansion board arrangement.
- ↑ Wikipedia, "Amstrad PC2286" (revision 1353136875). Retrieved 2026-10-02. BIOS settings backed by four AA cells on top of the base unit in the PC2000 series.
- ↑ Centre for Computing History, "Amstrad PC2286/40", exhibit CH1264. Retrieved 2026-10-02. The PC2000 series' CMOS backed by four AA cells under the monitor.
- ↑ 5.0 5.1 Audigy, "Help diagnosing fault with my childhood Amstrad PC2386/65", VOGONS, 15 November 2025. Retrieved 2026-10-02. Community report: a PC2386 supply repaired by replacing leaking capacitors and a faulty optocoupler; the machine booting from its 65 MB drive after the BIOS settings were re-entered; a later fault with stripes on the screen, unresolved.
- ↑ Tomek TRV, "Amstrad PC2386 floppy drive problem", VOGONS, 3 December 2025. Retrieved 2026-10-02. Community report: the Citizen OSDA-46 on a straight cable at ID 0, and other ID 0 drives not working in the PC2386; unresolved.
- ↑ 7.0 7.1 7.2 Kubik, PC Hoarder Patrol, Tomek TRV and rasteri, "Amstrad PC2386 keyboard", VOGONS, June 2020 – November 2025. Retrieved 2026-10-02. Community reports: the PC2386's 270-degree 5-pin DIN keyboard socket, keyboards 7220000503 and 7220000824 with the MK0006A controller board, repairing a keyboard by separating its membrane layers, the unused IDE connector on the main board.