Jump to content

Amstrad PC2086 Capacitor Replacement Guide

From RetroTechCollection
Amstrad PC2086 main PCB layout
PC2086 main board MC0065 (service manual p. 7)

Amstrad's service manual for the Amstrad PC2086 lists every electrolytic capacitor in the system unit with its value, voltage and part number, on the electrical parts list on page 4. The C6xx positions are on the power supply board (PCB601, MS0116); the rest are on the main board and the smaller boards.[1] One owner found a PC2086 rusty and with leaking capacitors. Another changed every electrolytic in the supply and still had no output, so measure the rails before and after; a third owner, whose supply worked, did not recall the supplies being a known weakness.[2][3]

Safety

[edit | edit source]

Warning: the supply runs from the mains, and C601 (150 µF 400 V) holds a dangerous charge after unplugging.

  • Unplug the machine, remove the supply (see the maintenance guide) and discharge C601 through a suitable resistor before working on the board.[1]
  • Replace F601 only with a 3.15 A time-lag 250 V fuse.[1]

Power supply board

[edit | edit source]
Power supply electrolytics (service manual p. 4)
Ref Value Voltage Amstrad part no.
C637 0.1 µF 50 V 150908
C605 0.22 µF 50 V 152546
C624 0.33 µF 50 V 176313
C602 1 µF 50 V 20062
C606 4.7 µF 100 V 175116
C629, C630 10 µF 16 V 20148
C610 22 µF 50 V 176316
C615 47 µF 16 V 20027
C616 47 µF 25 V 151640
C628 100 µF 10 V/16 V 20028
C631 100 µF 16 V 20028
C609, C619 100 µF 25 V 176318
C611 100 µF 35 V 176319
C608 100 µF 50 V 176320
C601 150 µF 400 V 171450
C613 330 µF 25 V 171652
C627 330 µF 35 V 176321
C623 1000 µF 16 V 1422158
C621, C622 3300 µF 16 V 171654
C618 3300 µF 35 V 171655

C637, C605 and C624, at 0.1 to 0.33 µF, are listed by Amstrad as electrolytics. Where Amstrad prints two voltages (10 V/16 V) either part was fitted; use the higher rating.[1]

Other boards

[edit | edit source]
Other electrolytics (service manual p. 4)
Ref Value Voltage Amstrad part no.
C401, C405 1 µF 50 V 20062
C580–C582, C808 10 µF 50 V 176314
C409 22 µF 25 V 176315
C300 25 µF (as printed) 25 V 176317
C402, C404, C801 47 µF 16 V 20027
C124, C403 100 µF 10 V/16 V 20028
C579 3300 µF 10 V/15 V (as printed) 152098

On a PC1640, a replacement for the fusible resistor R181 smoked until the 100 µF capacitor C124 was removed.[4] The PC2086 main board (MC0065) is a different board from the PC1640's (MC0040A) and its parts list has no R181, so the same designator does not mean the same circuit; trace C124 on the schematic before treating it as the cause of a floppy controller error.[1]

Procedure

[edit | edit source]
  1. Open the case, unplug the supply from the main board and lift it out.
  2. Discharge C601 and note the value, voltage and polarity of each electrolytic before removing it; the list above gives Amstrad's values.
  3. Replace the capacitors, cleaning any electrolyte from the board and checking the tracks underneath.
  4. Refit the supply and connect the main board and a drive as load.
  5. Set the rails with VR604, VR603, VR601 and VR602 to 5.15 V, 12.15 V, −5 V and −12.00 V at test points A to D, then set the +12 V protection with VR606 as described in the maintenance guide.[1]
[edit | edit source]

References

[edit | edit source]
  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Amstrad plc, PC2086 S/D/30 Personal Computer / PC12 MD / PC12 HRCD / PC14 CD / PC14 HRCD Monitors Service Manual. Hosted as File:Amstrad PC 2086 Service Manual.pdf, described at Amstrad PC 2086 Service Manual. Alignment instructions p. 3; electrical parts list p. 4 (electrolytic capacitors in the right-hand column); power supply schematic p. 18; monitor parts lists from p. 20.
  2. ↑ Ghislain, "Amstrad PC2086", Vintage Computer Federation Forums, January 2025. Retrieved 2026-10-02. Community report: a PC2086 found with rust and leaking capacitors.
  3. ↑ Ghislain, dorje and others, "Amstrad PC2086 PSU", Vintage Computer Federation Forums, June 2020 – November 2024. Retrieved 2026-10-02. Community reports: a full recap of the supply that did not cure a no-output fault; unloaded readings on a working supply; cwathen's reply of 21 June 2020 that the supplies were not a known weakness.
  4. ↑ jarcher1701, modem7 and others, "Amstrad PC1640 – Faulty Floppy Disk Controller or Disk Drive", Vintage Computer Federation Forums, October–December 2023 (page 5 of the thread). Retrieved 2026-10-02. Community repair on the PC1640: R181 burnt out and the floppy controller error; a replacement R181 smoked until C124 (100 µF) was removed.


Retrieved from "https://retrotechwiki.com/index.php?title=Amstrad_PC2086_Capacitor_Replacement_Guide&oldid=25324"