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Amstrad CPC 664 Capacitor Replacement Guide: Difference between revisions

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Rebuild from Amstrad's own CPC664 Electrical Parts List; remove unsourced function attributions; note the 464/664 differences. Banner removed.
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'''Every value on this page is taken from Amstrad's own Electrical Parts List for the CPC664''' in the service manual hosted on this wiki.<ref name="sm664">Amstrad Consumer Electronics plc, ''CPC664 Service Manual'', "Electrical Parts List CPC664", hosted at [[Amstrad CPC 664 Service Manual]]. Gives value, circuit reference and Amstrad part number for every capacitor, resistor and IC on the CPC664.</ref>
'''Every value on this page is taken from Amstrad's own Electrical Parts List for the CPC664''' in the service manual hosted on this wiki.<ref name="sm664">Amstrad Consumer Electronics plc, ''CPC664 Service Manual'', "Electrical Parts List CPC664", hosted at [[Amstrad CPC 664 Service Manual]]. Gives value, circuit reference and Amstrad part number for every capacitor, resistor and IC on the CPC664.</ref>


== ⚠️ What changed ==
== Safety ==
 
This page previously carried values and a "function" column that could not be traced to Amstrad's parts list. It has been rebuilt from that list. Two points worth noting:
 
* '''The CPC664 is not a CPC464 with a disk drive bolted on''', as far as the capacitor complement goes. It has '''no C322 and no C324''' — those are cassette-circuit parts on the [[Amstrad CPC 464|464]] and the 664 has a floppy drive instead. It gains C129, C316 and C317, and it carries five polystyrene capacitors where the 464 has three.
* '''Amstrad's parts list gives value, circuit reference and part number only.''' It does not state what any capacitor does. Functional descriptions have been removed rather than presented as fact; establishing them means reading the CPC664 CPU circuit diagram in the same manual.
 
== ⚠️ Safety ==


The computer runs from a low-voltage supply, but '''the CTM644 colour monitor and GT65 green monitor contain a CRT and mains-derived high voltage that persists after switch-off.''' See [[CRT Discharge Procedure]] before opening either. This page covers the computer.
The computer runs from a low-voltage supply, but '''the CTM644 colour monitor and GT65 green monitor contain a CRT and mains-derived high voltage that persists after switch-off.''' See [[CRT Discharge Procedure]] before opening either. This page covers the computer.
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'''Eleven electrolytics across five values''' — a smaller complement than the 464's thirteen.
'''Twelve electrolytics across five values''' — a smaller complement than the 464's fourteen. Note that the 664 keeps the cassette ''interface'' (IC301, IC302, the tape motor relay RY301 and the 5-pin DIN socket J302 for an external recorder) even though it has no cassette deck, which is why the 300-series capacitors are present.


== Ceramic capacitors ==
== Ceramic capacitors ==

Latest revision as of 11:05, 27 September 2026

Capacitor replacement for the Amstrad CPC 664.

Every value on this page is taken from Amstrad's own Electrical Parts List for the CPC664 in the service manual hosted on this wiki.[1]

Safety

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The computer runs from a low-voltage supply, but the CTM644 colour monitor and GT65 green monitor contain a CRT and mains-derived high voltage that persists after switch-off. See CRT Discharge Procedure before opening either. This page covers the computer.

Electrolytic capacitors

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CPC664 electrolytic capacitors[1]
Value Circuit reference Amstrad part no.
100 µF / 16 V C315 20028
100 µF / 10 V C301, C304 20028
47 µF / 10 V C129, C303, C306 1400244
22 µF / 10 V C308 20025
1 µF / 50 V C309, C311, C314, C316, C317 20062

Twelve electrolytics across five values — a smaller complement than the 464's fourteen. Note that the 664 keeps the cassette interface (IC301, IC302, the tape motor relay RY301 and the 5-pin DIN socket J302 for an external recorder) even though it has no cassette deck, which is why the 300-series capacitors are present.

Ceramic capacitors

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CPC664 ceramic capacitors[1]
Value Circuit reference Amstrad part no.
0.1 µF / 16 V C101–C128, C201–C213 24020
470 pF / 50 V C307 24004
270 pF / 50 V C313 900400
220 pF / 50 V C133–C135, C310 400107
68 pF / 50 V C130, C131 170826
47 pF / 50 V C132 24002

Note the C201–C213 block — those are on the disk interface section, which the 464 does not have.[1]

Polystyrene capacitors

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CPC664 polystyrene capacitors[1]
Value Circuit reference Amstrad part no.
0.1 µF C319 170852
0.068 µF C302 170219
0.047 µF C318 1409178
0.01 µF C305 170218
0.001 µF C312 170217

Polystyrene capacitors deform at soldering temperatures that an electrolytic shrugs off. Work quickly and keep the iron off the body.

A note from Amstrad on the disk PCB

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The parts list carries an explicit instruction: no part numbers are given for any parts on that PCB, and Amstrad directed service agents to return the board complete for replacement rather than repair it to component level.[1] That is Amstrad's position in period, not a statement that the board is unrepairable today — but it does mean this manual will not give you component values for the disk PCB.

Before you start

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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Amstrad Consumer Electronics plc, CPC664 Service Manual, "Electrical Parts List CPC664", hosted at Amstrad CPC 664 Service Manual. Gives value, circuit reference and Amstrad part number for every capacitor, resistor and IC on the CPC664.
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