Acorn System 5 Capacitor Replacement Guide: Difference between revisions
Create Acorn System series page (cited; sourced from System manuals/catalogue) |
Add machine photo |
||
| Line 1: | Line 1: | ||
<templatestyles src="Template:StyledTable/styles.css" /> | <templatestyles src="Template:StyledTable/styles.css" /> | ||
[[File:Acorn System 5.jpg|thumb|360x360px|Acorn System 5 Eurocard rack with two floppy drives.]] | |||
This guide covers recapping the '''[[Acorn System 5]]''' (late 1982). As a Eurocard rack it has per-card capacitors (a regulator electrolytic plus ceramic decouplers on each card), and as a fully-cased machine it also has bulk smoothing electrolytics in its integral mains power supply. The [[Acorn System 5 Handbook]] documents the boards.<ref name="hb">[[Acorn System 5 Handbook]] (1 March 1983), Acorn Computers — hosted on this wiki. Per-board reference for the System 5 Eurocards. The [[Acorn System Catalogue]] and [[Acorn System 1 Technical Manual]] give the wider Eurocard capacitor detail.</ref> | This guide covers recapping the '''[[Acorn System 5]]''' (late 1982). As a Eurocard rack it has per-card capacitors (a regulator electrolytic plus ceramic decouplers on each card), and as a fully-cased machine it also has bulk smoothing electrolytics in its integral mains power supply. The [[Acorn System 5 Handbook]] documents the boards.<ref name="hb">[[Acorn System 5 Handbook]] (1 March 1983), Acorn Computers — hosted on this wiki. Per-board reference for the System 5 Eurocards. The [[Acorn System Catalogue]] and [[Acorn System 1 Technical Manual]] give the wider Eurocard capacitor detail.</ref> | ||
Latest revision as of 21:54, 17 June 2026
This guide covers recapping the Acorn System 5 (late 1982). As a Eurocard rack it has per-card capacitors (a regulator electrolytic plus ceramic decouplers on each card), and as a fully-cased machine it also has bulk smoothing electrolytics in its integral mains power supply. The Acorn System 5 Handbook documents the boards.[1]
Per-card capacitors
[edit | edit source]On each Eurocard the recap target is the +5 V regulator electrolytic; the ceramic decouplers are stable and left in place. Read each value from the card and its circuit diagram, and fit a 105 °C low-ESR part of equal capacitance and equal-or-higher voltage, observing polarity.
- CPU card (6502 or 6502A) — regulator electrolytic plus decouplers (the 1 MHz 6502 card follows the Acorn System 1 values).
- VDU card (80×25 or 40×25) — regulator electrolytic plus decouplers.
- 32 KB DRAM cards — regulator electrolytic plus decouplers; the DRAM cards draw the most current, so their regulator electrolytics are worth checking first.
- Floppy-controller and Econet cards — regulator electrolytic plus decouplers.
⚠️ Mains power supply
[edit | edit source]The System 5's integral PSU is mains-powered and contains the bulk smoothing electrolytics and mains-side suppression parts. Disconnect the mains lead and discharge the bulk capacitor before any PSU work. Recap the PSU only if competent with mains supplies; otherwise replace it. Read each value from the fitted part.
Procedure (per card)
[edit | edit source]- Power off; remove the card from the backplane.
- Record each electrolytic's value, voltage and polarity.
- Desolder, clean the holes, fit the new part with correct polarity, solder and trim.
- Verify +5 V on the card and refit.
Related pages
[edit | edit source]- Acorn System 5
- Acorn System 5 Maintenance Guide
- Acorn System 5 Troubleshooting Guide
- Acorn System 1 Capacitor Replacement Guide · Capacitor Failure Symptoms
References
[edit | edit source]- ↑ Acorn System 5 Handbook (1 March 1983), Acorn Computers — hosted on this wiki. Per-board reference for the System 5 Eurocards. The Acorn System Catalogue and Acorn System 1 Technical Manual give the wider Eurocard capacitor detail.