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Rewrite from Commodore's 250469-01 parts list: previous page listed C88/C89/C90 as electrolytics, but those are ceramics on this board. Banner removed; fully cited.
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Recapping a '''[[Commodore 64C]]''' — and any [[Commodore 64]] built on the '''250469 "short board"''' — restores stable supply rails and removes a common source of audio and video noise.


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'''Every value on this page is taken from Commodore's own parts list''' for PCB assembly 250469-01 in the [[Commodore C64 Service Manual|C64 / C64C Service Manual]] (March 1992).<ref name="sm">Commodore Business Machines, ''C64 / C64C Service Manual'', March 1992, hosted at [[Commodore C64 Service Manual]]. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.</ref>


Replacing the electrolytic capacitors (recapping) in your '''Commodore 64C''' is a vital preventative measure to ensure stable operation, clear video and audio output, and long-term reliability. As these components age, they can cause erratic behaviour, power instability, video artefacts, and leackage. Recapping your 64C restores original performance and protects the chips from power-related faults.
== ⚠️ A correction, and an important one ==


== Visual Inspection & Failure Signs ==
An earlier version of this page listed the short board's electrolytics as '''C88 2200 µF, C89 1000 µF, C90 330 µF''' with C91 "not fitted".


Before recapping, examine all electrolytic capacitors for these common failure indicators:
'''Those designators are not electrolytic capacitors on this board at all.''' In Commodore's parts list for 250469-01, '''C86–C88 are 220 pF ceramics''' and '''C90 is a 470 pF ceramic'''.<ref name="sm">Commodore Business Machines, ''C64 / C64C Service Manual'', March 1992, hosted at [[Commodore C64 Service Manual]]. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.</ref> The old page appears to have carried the long-board designators across to the short board and attached invented values to them.


* '''Bulging or domed tops''' – Indicates internal gas pressure and imminent failure.
The short board uses a completely different numbering scheme from the long boards. '''If you worked from this page before September 2026, check what you fitted and where.'''
* '''Leaking electrolyte''' – Brown, green, or white residue at the base of the capacitor.
* '''Corrosion or PCB staining''' – Green/black marks or discolouration around pads.
* '''Unusual behaviour''' – Audio hum, video glitches, or random resets can often be traced to failing capacitors.


If any capacitor shows signs of distress, it is strongly recommended to replace '''all''' electrolytic capacitors on the board.
== Which board is this? ==


== Commodore 64C Capacitor List ==
The '''250469''' short board is the one used in the C64C slim case, and in late "bread bin" machines. The assembly number is silkscreened on the board. For the earlier long boards — 326298, 250407, 250425 and 250466 — see [[Commodore 64 Capacitor Replacement Guide]], which lists a different and non-overlapping set of parts.


The Commodore 64C (board Assy 250469 and variants) uses a revised, cost-reduced PCB with fewer and smaller electrolytic capacitors compared to earlier C64 models. Always cross-check values with your board’s silkscreen, as minor revisions exist.
== Electrolytic capacitors — 250469-01 ==


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{| class="wikitable styled-table" style="width:100%; text-align:left;"
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''250469-01 (C64-E / 64C) electrolytics'''<ref name="sm">Commodore Business Machines, ''C64 / C64C Service Manual'', March 1992, hosted at [[Commodore C64 Service Manual]]. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.</ref>
|+'''Commodore 64C (Assy 250469) Electrolytic Capacitors'''
! Ref !! Value !! Rating !! Package !! Commodore part no.
! Ref !! Capacitance !! Voltage !! Circuit / Rail !! Notes
|-
| '''C63''' || 1000 µF || 16 V || Axial || 900101-52
|-
| '''C63''' ''(second entry — see note)'' || 2200 µF || 16 V || Axial || 900101-33
|-
|-
| C88 || 2,200 µF || 10 V || Main +5 V bulk || Main filter for logic supply
| '''C66''' || 470 µF || 35 V || Radial || 900301-35
|-
|-
| C89 || 1,000 µF || 10 V || VIC-II local decoupling || Sits near video chip (8565/8562)
| '''C43''' || 220 µF || 16 V || Radial || 900100-18
|-
|-
| C90 || 330 µF || 10 V || SID 8580 analogue +9 V || Audio rail filter
| '''C65''' || 220 µF || 25 V || Radial || 900100-03
|-
|-
| C91 || – || – || – || Not fitted (12 V rail deleted)
| '''C58''' || 100 µF || 16 V || Radial || 900100-40
|-
|-
| C15 || 10 µF || 16 V || Reset RC timer || Ensures reliable power-on reset
| '''C36''' || 47 µF || 16 V || Radial || 900100-33
|-
|-
| C38 || 47 µF || 16 V || Audio DC block || Lower value for 8580 SID bias
| '''C44''' || 22 µF || 50 V || Radial || 251079-06
|-
|-
| C70 || 2.2 µF || 50 V || Chroma coupling (RF modulator) || Small foil can, optional if modulator removed
| '''C77''' || 10 µF || 25 V || Radial || 900100-01
|-
|-
| C71, C72 || 47 µF || 16 V || RF modulator 5 V/audio buffer || Two cans inside modulator can
| '''C59''' || 4.7 µF || 25 V || Radial || 900100-11
|}
|}


''If your board is a rare 250469-Aldi variant with a 6581 SID, it may include C92 (470 µF, 16 V) for a linear 12 V regulator. Replace this if present.''
'''Note on C63.''' Commodore's printed parts list for this assembly contains '''two entries for C63''' — 1000 µF 16 V (900101-52) and 2200 µF 16 V (900101-33).<ref name="sm">Commodore Business Machines, ''C64 / C64C Service Manual'', March 1992, hosted at [[Commodore C64 Service Manual]]. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.</ref> This wiki has not been able to determine whether that reflects a running change or an error in the manual. '''Read the value off your own board and fit like for like'''; either part is physically and electrically reasonable in that position, and the higher value will not do harm.


=== SMD Capacitors ===
== What is not an electrolytic on this board ==
The standard 64C PCB does '''not''' use SMD electrolytics; all are through-hole types. If you encounter SMD cans, your board may be a late third-party or repair replacement—verify values before ordering.


== Capacitor Replacement Procedure ==
Worth stating plainly, because the previous version of this page got it wrong:<ref name="sm">Commodore Business Machines, ''C64 / C64C Service Manual'', March 1992, hosted at [[Commodore C64 Service Manual]]. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.</ref>


# '''Disassemble the C64C''' – Remove case screws (three at rear, two under keyboard), gently lift the keyboard, and unplug the LED and keyboard connectors.
{| class="wikitable styled-table" style="width:80%; text-align:left;"
# '''Remove the RF shield''' – Desolder or carefully unclip the folded metal tabs. Set aside for reassembly.
! Ref !! What it actually is
# '''Document capacitor positions''' – Take photos or label wires if unsure.
|-
# '''Desolder old capacitors''' – Use solder wick and flux. Commodore used high-melting-point solder; set your iron to at least '''375 °C'''. Be patient with ground planes.
| C2–C4, C6, C76, C90 || Ceramic, 470 pF 50 V
# '''Clean pads''' – Remove any residual solder and clean with isopropyl alcohol.
|-
# '''Install new capacitors''' – Match polarity (long lead = positive) and ensure correct lead spacing (5 mm or 7.5 mm). Keep capacitor height below 17 mm for shield clearance.
| C74 || Ceramic, 1000 pF 50 V
# '''Inspect work''' – Check for solder bridges or cold joints.
|-
# '''Reassemble and test''' – Refit the shield, reconnect keyboard and LED, and close the case.
| C80, C81 || Ceramic, 1800 pF 50 V / 2200 pF 25 V depending on the list
 
|-
== Recommended Tools & Parts ==
| C86–C88 || Ceramic, 220 pF 50 V
 
* '''Temperature-controlled soldering iron''' (70 W, 2 mm chisel tip)
* '''Solder wick and desoldering pump'''
* '''Leaded 63/37 or quality lead-free solder'''
* '''105 °C, low-ESR radial capacitors''' (brands: Nichicon PW/PS, Panasonic FR/FC, Rubycon ZLH)
* '''Isopropyl alcohol (IPA) and nylon brush'''
* '''Kapton tape''' (to insulate capacitors near the RF shield)
* '''Multimeter''' (for continuity and voltage checks)
* '''Protective eyewear'''
 
== Post-Recap Voltage & Ripple Checks ==
 
After recapping, verify the main power rails with a multimeter or oscilloscope:
 
{| class="wikitable styled-table" style="width:80%; text-align:center;"
|+'''Commodore 64C Power Rails (No Cartridge, BASIC READY)'''
! Test Point !! Expected Voltage !! Max Ripple (p-p)
|-
|-
| +5 V (PLA pin 24) || 4.95 – 5.10 V || < 50 mV
| C94 || Ceramic, 150 pF 50 V
|-
|-
| +9 V (SID 8580 pin 28) || 8.7 – 9.3 V || < 100 mV
| C70, C71 || Ceramic, 22000 pF
|-
|-
| 9 VAC (user port pins 10/11) || 8.5 – 10 V rms || Sine-like
| C1, C7, C28–C30 || Ceramic, 0.1 µF 25 V
|}
|}


''If you observe video shimmer, audio buzz, or random resets, recheck your soldering and capacitor polarity. Ripple above 100 mV on any rail indicates a possible fault.''
Ceramics of this type do not age the way aluminium electrolytics do and are not part of a routine recap.
 
== Before you start ==
 
* '''Work from your own board's silkscreen.''' The assembly number tells you which list applies; the board itself is the final authority.
* Anti-static precautions throughout. The 8500, 8565/8562 VIC-II, 8580 SID and the Super PLA are the parts you cannot casually replace.
* See [[Capacitor Failure Symptoms]] for recognising a failed part and [[Recommended Tools]] for the workshop kit.
 
== Related pages ==


== Additional Tips ==
* [[Commodore 64C]] · [[Commodore 64C General Maintenance]] · [[Commodore 64]] · [[Commodore 64 Capacitor Replacement Guide]]
* '''[[Commodore C64 Service Manual]]''' — the source for every value on this page
* [[Capacitor Failure Symptoms]] · [[Recommended Tools]]


* '''Test your power supply first''' – A faulty “brick” can destroy new capacitors and chips.
== References ==
* '''Keep capacitor diameter similar''' – Especially for C89 and C90, as the RF shield may press against them.
* '''RF modulator removal''' – If you have performed a composite/S-video mod and removed the RF modulator, C70, C71, and C72 may be omitted.
* '''Reseat socketed chips''' – After recapping, temperature changes may unseat the VIC-II, SID, or PLA.
* '''Store your C64C in a dry environment''' – Moisture accelerates capacitor degradation.
* '''Dispose of old capacitors responsibly''' – Use an electronics recycling facility.


== Related Pages ==
<references />
* [[Commodore 64C Troubleshooting Guide]]
* [[Commodore 64 Power-Supply Protector (C64 Saver)]]
* [[Commodore 64 Video Output Upgrades]]


[[Category:Commodore Systems]]
[[Category:Commodore Systems]]
[[Category:Capacitor Replacement Guides]]
[[Category:Capacitor Replacement Guides]]

Revision as of 21:59, 21 September 2026

Recapping a Commodore 64C — and any Commodore 64 built on the 250469 "short board" — restores stable supply rails and removes a common source of audio and video noise.

Every value on this page is taken from Commodore's own parts list for PCB assembly 250469-01 in the C64 / C64C Service Manual (March 1992).[1]

⚠️ A correction, and an important one

An earlier version of this page listed the short board's electrolytics as C88 2200 µF, C89 1000 µF, C90 330 µF with C91 "not fitted".

Those designators are not electrolytic capacitors on this board at all. In Commodore's parts list for 250469-01, C86–C88 are 220 pF ceramics and C90 is a 470 pF ceramic.[1] The old page appears to have carried the long-board designators across to the short board and attached invented values to them.

The short board uses a completely different numbering scheme from the long boards. If you worked from this page before September 2026, check what you fitted and where.

Which board is this?

The 250469 short board is the one used in the C64C slim case, and in late "bread bin" machines. The assembly number is silkscreened on the board. For the earlier long boards — 326298, 250407, 250425 and 250466 — see Commodore 64 Capacitor Replacement Guide, which lists a different and non-overlapping set of parts.

Electrolytic capacitors — 250469-01

250469-01 (C64-E / 64C) electrolytics[1]
Ref Value Rating Package Commodore part no.
C63 1000 µF 16 V Axial 900101-52
C63 (second entry — see note) 2200 µF 16 V Axial 900101-33
C66 470 µF 35 V Radial 900301-35
C43 220 µF 16 V Radial 900100-18
C65 220 µF 25 V Radial 900100-03
C58 100 µF 16 V Radial 900100-40
C36 47 µF 16 V Radial 900100-33
C44 22 µF 50 V Radial 251079-06
C77 10 µF 25 V Radial 900100-01
C59 4.7 µF 25 V Radial 900100-11

Note on C63. Commodore's printed parts list for this assembly contains two entries for C63 — 1000 µF 16 V (900101-52) and 2200 µF 16 V (900101-33).[1] This wiki has not been able to determine whether that reflects a running change or an error in the manual. Read the value off your own board and fit like for like; either part is physically and electrically reasonable in that position, and the higher value will not do harm.

What is not an electrolytic on this board

Worth stating plainly, because the previous version of this page got it wrong:[1]

Ref What it actually is
C2–C4, C6, C76, C90 Ceramic, 470 pF 50 V
C74 Ceramic, 1000 pF 50 V
C80, C81 Ceramic, 1800 pF 50 V / 2200 pF 25 V depending on the list
C86–C88 Ceramic, 220 pF 50 V
C94 Ceramic, 150 pF 50 V
C70, C71 Ceramic, 22000 pF
C1, C7, C28–C30 Ceramic, 0.1 µF 25 V

Ceramics of this type do not age the way aluminium electrolytics do and are not part of a routine recap.

Before you start

  • Work from your own board's silkscreen. The assembly number tells you which list applies; the board itself is the final authority.
  • Anti-static precautions throughout. The 8500, 8565/8562 VIC-II, 8580 SID and the Super PLA are the parts you cannot casually replace.
  • See Capacitor Failure Symptoms for recognising a failed part and Recommended Tools for the workshop kit.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Commodore Business Machines, C64 / C64C Service Manual, March 1992, hosted at Commodore C64 Service Manual. Parts list for PCB assembly 250469-01 (C64-E), giving capacitance, voltage rating, package and Commodore part number for every capacitor on the short board.
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