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Rebuilt from sources: board is 820-0364-A with 11 SMD electrolytics (9x47uF 16V, 2x100uF 6.3V) - the previous 10-row C1-C10 table listed 10uF parts the board does not have. Corrected the CR2032 advice against Apple's own 3.0V replace threshold; added processor-removal-tool note, PSU and PDS facts. Refs added; {{Unverified data}} cleared
 
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{{Unverified data}}
Recapping the '''Macintosh LC 475''' and its identical twin the
Replacing the electrolytic capacitors (recapping) in the '''Macintosh LC 475''' ensures long-term reliability. The LC 475/Quadra 605 is generally easier to recap than earlier LC models, with fewer capacitors and a simpler layout.
'''[[Macintosh Quadra 605|Quadra 605]]''' is straightforward by the standards of this family: eleven
surface-mount electrolytics, all on the top side of the board, and no silkscreen traps.


== Symptoms of Capacitor Failure ==
The logic board is '''820-0364-A''' (1993). It is a different board from the LC III, with a different
capacitor complement, so the two lists are not interchangeable. The same board is used by the
[[Macintosh Performa 475]]/476.<ref name="ss-p400">Apple Computer, ''Service Source: Macintosh Performa 400 Series'' — covers the Performa 400/405, 410, 430, 450, 460/466/467 and 475/476. Hosted on this wiki as [[:File:Performa 400 series.pdf]]; see [[Macintosh Performa 400 Series Service Source]].</ref>


* '''No audio or distorted audio'''
Tools, removal and fitting procedure, power supply data and battery information are common to the whole
* '''Boot failures or instability'''
"pizza box" family and live on [[Macintosh LC Capacitor Replacement Guide]]. This page carries what is
* '''Visible electrolyte leakage''' — Less common on LC 475 than earlier LCs
specific to the LC 475.
* '''Corrosion on PCB traces'''


== Capacitor List ==
== Symptoms of capacitor failure ==


=== Logic Board Capacitors ===
The same pattern as the rest of the family — sound loss first, then intermittent starting, then
visible residue and corroded copper — but generally less advanced, because these boards are two to
three years younger than the LC and LC II and use fewer, larger capacitors. That is a difference of
degree, not of kind: an unrecapped 820-0364 board in 2026 still needs doing.


The LC 475 logic board contains fewer surface-mount electrolytic capacitors than earlier LC models.
Unlike the LC III, the LC 475's bulk capacitor on the −5 V rail is wired the correct way round,
so an LC 475 with serial port faults after a recap is a genuine fault rather than the LC III's known
silkscreen error.<ref name="ddb">Doug Brown, [https://www.downtowndougbrown.com/2024/11/the-capacitor-that-apple-soldered-incorrectly-at-the-factory/ “The capacitor that Apple soldered incorrectly at the factory”], 26 November 2024. Continuity and voltage measurements showing that C22 on the LC III board has its positive terminal on −5 V and its negative terminal on ground; comparison with the LC, LC II and LC 475 boards, which are wired the other way round; and the reported consequences of fitting a tantalum in the silkscreened orientation.</ref>


{| class="wikitable" style="width:80%; text-align:center;"
See [[Macintosh LC Capacitor Replacement Guide]] for the full symptom list and
|+ '''Macintosh LC 475 Logic Board Capacitors'''
[[Capacitor Failure Symptoms]] for the general picture.
|-
! Designator !! Capacitance !! Voltage !! Type
|-
| C1 || 10 µF || 16V || SMD Electrolytic
|-
| C2 || 10 µF || 16V || SMD Electrolytic
|-
| C3 || 10 µF || 16V || SMD Electrolytic
|-
| C4 || 10 µF || 16V || SMD Electrolytic
|-
| C5 || 47 µF || 16V || SMD Electrolytic
|-
| C6 || 47 µF || 16V || SMD Electrolytic
|-
| C7 || 47 µF || 16V || SMD Electrolytic
|-
| C8 || 47 µF || 16V || SMD Electrolytic
|-
| C9 || 100 µF || 6.3V || SMD Electrolytic
|-
| C10 || 100 µF || 6.3V || SMD Electrolytic
|}


[[File:Mac LC 475 Recap Guide.jpg|center|thumb|600px|Macintosh LC 475/Quadra 605 logic board capacitor locations. Source: [https://recapamac.com.au/macintosh-lc475/ Recap-a-Mac]]]
== Macintosh LC 475 / Quadra 605 logic board (820-0364-A) ==


'''Note:''' The exact designators may vary. Consult a logic board diagram or use values from the existing capacitors.
Eleven surface-mount electrolytic capacitors:


=== Power Supply Capacitors ===
* '''9 × 47 µF 16 V'''
* '''2 × 100 µF 6.3 V'''


Refer to the [[Macintosh LC Power Supply Recap Guide]] for PSU-specific information. The LC 475 uses a 30W power supply.
[[File:Mac LC 475 Recap Guide.jpg|center|thumb|700px|Macintosh LC 475 / Quadra 605 logic board
820-0364-A. Each capacitor is marked with its value, working voltage and positive terminal. Source:
Recap-a-Mac.]]


[[File:Mac LC PSU Recap Guide.jpg|center|thumb|600px|Macintosh LC power supply capacitor locations. Source: [https://recapamac.com.au/macintosh-lc-power-supply/ Recap-a-Mac]]]
'''On sourcing:''' these figures come from a single community source, Recap-a-Mac's annotated photograph
of an 820-0364-A board.<ref name="ram-475">[https://recapamac.com.au/macintosh-lc475/ Recap-a-Mac — Macintosh LC 475 / Quadra 605]. Annotated photograph of the 820-0364-A logic board. Hosted on this wiki as [[:File:Mac LC 475 Recap Guide.jpg]]. Secondary source.</ref> Unlike the LC, LC II and LC III boards, this one has no second
published list to cross-check against — Console5 does not carry an LC 475 entry, and Apple never
published component-level data for any Macintosh of this era. The photograph is therefore both the value
list and the location map: work from it rather than from a designator table, and read the value printed
on each capacitor body before you lift it.


== PRAM Battery Upgrade ==
== Power supply and battery ==


When recapping the LC 475, consider upgrading the PRAM battery holder:
Shared with the rest of the family: Apple power supply '''661-1733''', a universal 100–240 VAC
auto-ranging switch-mode unit, and lithium battery '''742-0011'''.<ref name="ss-lc">Apple Computer, ''Service Source: Macintosh LC Series / Quadra 605'' — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as [[:File:Quadra 605.lc series.pdf]]; see [[Macintosh LC Series/ Quadra 605 Service Source]].</ref> The supply exists in six known
vendor variants with different capacitor complements — identify yours by its label before ordering.
Full data on [[Macintosh LC Capacitor Replacement Guide]].


* Replace the original 1/2 AA battery holder with a '''CR2032 coin cell holder'''
Apple rates the Quadra 605 at 26 W maximum, monitor excluded, and gives its mains frequency range as
* CR2032 cells are widely available and easier to replace
50–60 Hz against 47–63 Hz for the rest of the LC series.<ref name="ss-lc" />
* Ensure correct voltage (3V for CR2032 vs. 3.6V for 1/2 AA)—this slight difference is acceptable


== Capacitor Replacement Procedure ==
=== The PRAM battery, and the CR2032 question ===


=== Tools Required ===
Apple's part is a '''3.6 V lithium half-AA''', part number '''742-0011''', in a clip-in
holder.<ref name="ss-lc" /> Apple's service check is to measure it on the 10 V DC range and replace it if it
reads '''below 3.0 V'''.<ref name="ss-lc" />


* Temperature-controlled soldering iron (recommended: 300-350°C)
Fitting a CR2032 holder in place of the original is a popular modification, because CR2032 cells are
* Fine tip for SMD work
cheap and available everywhere. Be clear about the trade-off before you do it: a CR2032 is a nominal
* Desoldering braid or solder wick
'''3.0 V''' cell, which is exactly the voltage at which Apple's own procedure says to throw the
* Flux (no-clean recommended)
battery away. A fresh CR2032 starts life at Apple's replace-now threshold and falls from there, so
* Isopropyl alcohol (99%)
expect a shorter useful life and, on a machine that is marginal, PRAM that does not hold. A 3.6 V
* Soft brush (ESD-safe)
lithium half-AA in a holder — rather than a soldered-in cell — gives the original voltage with
* Multimeter
the same convenience.
* Replacement SMD electrolytic capacitors


=== Procedure ===
Whatever you fit, fit it in a holder and take it out when the machine goes into storage. See
[[Battery Explosion, Capacitor or Corrosion Damage]] and [[Battery Refurbishment]].


# '''Remove the logic board''' — Disconnect all cables, remove screws, and carefully lift the board.
== Working around the processor ==
# '''Remove the CPU''' — The socketed 68LC040 should be removed to prevent damage during work.
# '''Document capacitor positions''' — Note polarity markings before removal.
# '''Clean the area''' — Remove any leaked electrolyte with isopropyl alcohol.
# '''Remove old capacitors''' — Heat one pad while gently lifting the capacitor. Alternate between pads.
# '''Clean the pads''' — Remove old solder with desoldering braid. Clean with IPA.
# '''Inspect for damage''' — Check traces and vias for corrosion.
# '''Install new capacitors''' — Observe polarity. The stripe on the capacitor indicates negative.
# '''Clean residue''' — Remove flux with isopropyl alcohol.
# '''Test continuity''' — Verify no shorts between +5V, +12V, and ground.
# '''Reinstall CPU''' — Carefully reseat the 68LC040.
# '''Reassemble and test'''


== Important Notes ==
The 68LC040 is socketed. Apple's own upgrade procedure for the LC 475 and Quadra 605 removes it from the
logic board with a dedicated processor removal tool, which Apple sells as a separate service
part.<ref name="ss-lc" /> Levering a PGA processor out with a screwdriver bends pins and cracks board corners; if
you take it out to get at the board, use the proper tool or leave it in place.


* '''Simpler recap''' — The LC 475 has fewer capacitors and is easier to work on than earlier LCs.
== Things that are not faults ==
* '''Polarity matters''' — SMD electrolytics will fail if installed backwards.
* '''CPU care''' — Remove the socketed CPU before working to avoid accidental damage.
* '''PRAM battery''' — Consider the CR2032 upgrade while the board is disassembled.


== Related Pages ==
* '''No FPU.''' The 68LC040 has no floating-point unit. Software that requires one will refuse to run on
  a standard LC 475 or Quadra 605. Apple's specification confirms the 68LC040 fitting.<ref name="ss-lc" />
* '''Two VRAM SIMMs.''' Apple ships the LC 475 and Quadra 605 with two 256 K VRAM SIMMs, upgradable
  to 1 MB — a pair of small modules in the sockets is the factory configuration, not a
  bodge.<ref name="ss-lc" />
* '''The PDS will not take an accelerator.''' Apple states that the 114-pin slot accepts LC-compatible
  I/O, display, network and video capture cards but '''does not''' support 030 processor accelerator or
  cache cards.<ref name="ss-lc" />
 
== Related pages ==


* [[Macintosh LC 475]]
* [[Macintosh LC 475]]
* [[Macintosh Quadra 605]]
* [[Macintosh LC 475 General Maintenance]]
* [[Macintosh LC 475 General Maintenance]]
* [[Macintosh LC 475 Troubleshooting]]
* [[Macintosh LC 475 Troubleshooting]]
* [[Macintosh LC Capacitor Replacement Guide]] — shared procedure, power supply and battery
* [[Macintosh LC Series/ Quadra 605 Service Source]]


== External Resources ==
== References ==
 
<references />
* [https://recapamac.com.au/macintosh-lc475/ Recap-a-Mac: Macintosh LC 475/Quadra 605 Capacitor Guide]


[[Category:Apple Vintage Computers]]
[[Category:Apple Vintage Computers]]
[[Category: Capacitor Replacement Guides]]
[[Category:Capacitor Replacement Guides]]
{{Navbox-AppleVintage|state=collapsed}}

Latest revision as of 00:41, 23 September 2026

Recapping the Macintosh LC 475 and its identical twin the Quadra 605 is straightforward by the standards of this family: eleven surface-mount electrolytics, all on the top side of the board, and no silkscreen traps.

The logic board is 820-0364-A (1993). It is a different board from the LC III, with a different capacitor complement, so the two lists are not interchangeable. The same board is used by the Macintosh Performa 475/476.[1]

Tools, removal and fitting procedure, power supply data and battery information are common to the whole "pizza box" family and live on Macintosh LC Capacitor Replacement Guide. This page carries what is specific to the LC 475.

Symptoms of capacitor failure

[edit | edit source]

The same pattern as the rest of the family — sound loss first, then intermittent starting, then visible residue and corroded copper — but generally less advanced, because these boards are two to three years younger than the LC and LC II and use fewer, larger capacitors. That is a difference of degree, not of kind: an unrecapped 820-0364 board in 2026 still needs doing.

Unlike the LC III, the LC 475's bulk capacitor on the −5 V rail is wired the correct way round, so an LC 475 with serial port faults after a recap is a genuine fault rather than the LC III's known silkscreen error.[2]

See Macintosh LC Capacitor Replacement Guide for the full symptom list and Capacitor Failure Symptoms for the general picture.

Macintosh LC 475 / Quadra 605 logic board (820-0364-A)

[edit | edit source]

Eleven surface-mount electrolytic capacitors:

  • 9 × 47 µF 16 V
  • 2 × 100 µF 6.3 V
Macintosh LC 475 / Quadra 605 logic board 820-0364-A. Each capacitor is marked with its value, working voltage and positive terminal. Source: Recap-a-Mac.

On sourcing: these figures come from a single community source, Recap-a-Mac's annotated photograph of an 820-0364-A board.[3] Unlike the LC, LC II and LC III boards, this one has no second published list to cross-check against — Console5 does not carry an LC 475 entry, and Apple never published component-level data for any Macintosh of this era. The photograph is therefore both the value list and the location map: work from it rather than from a designator table, and read the value printed on each capacitor body before you lift it.

Power supply and battery

[edit | edit source]

Shared with the rest of the family: Apple power supply 661-1733, a universal 100–240 VAC auto-ranging switch-mode unit, and lithium battery 742-0011.[4] The supply exists in six known vendor variants with different capacitor complements — identify yours by its label before ordering. Full data on Macintosh LC Capacitor Replacement Guide.

Apple rates the Quadra 605 at 26 W maximum, monitor excluded, and gives its mains frequency range as 50–60 Hz against 47–63 Hz for the rest of the LC series.[4]

The PRAM battery, and the CR2032 question

[edit | edit source]

Apple's part is a 3.6 V lithium half-AA, part number 742-0011, in a clip-in holder.[4] Apple's service check is to measure it on the 10 V DC range and replace it if it reads below 3.0 V.[4]

Fitting a CR2032 holder in place of the original is a popular modification, because CR2032 cells are cheap and available everywhere. Be clear about the trade-off before you do it: a CR2032 is a nominal 3.0 V cell, which is exactly the voltage at which Apple's own procedure says to throw the battery away. A fresh CR2032 starts life at Apple's replace-now threshold and falls from there, so expect a shorter useful life and, on a machine that is marginal, PRAM that does not hold. A 3.6 V lithium half-AA in a holder — rather than a soldered-in cell — gives the original voltage with the same convenience.

Whatever you fit, fit it in a holder and take it out when the machine goes into storage. See Battery Explosion, Capacitor or Corrosion Damage and Battery Refurbishment.

Working around the processor

[edit | edit source]

The 68LC040 is socketed. Apple's own upgrade procedure for the LC 475 and Quadra 605 removes it from the logic board with a dedicated processor removal tool, which Apple sells as a separate service part.[4] Levering a PGA processor out with a screwdriver bends pins and cracks board corners; if you take it out to get at the board, use the proper tool or leave it in place.

Things that are not faults

[edit | edit source]
  • No FPU. The 68LC040 has no floating-point unit. Software that requires one will refuse to run on
 a standard LC 475 or Quadra 605. Apple's specification confirms the 68LC040 fitting.[4]
  • Two VRAM SIMMs. Apple ships the LC 475 and Quadra 605 with two 256 K VRAM SIMMs, upgradable
 to 1 MB — a pair of small modules in the sockets is the factory configuration, not a
 bodge.[4]
  • The PDS will not take an accelerator. Apple states that the 114-pin slot accepts LC-compatible
 I/O, display, network and video capture cards but does not support 030 processor accelerator or
 cache cards.[4]
[edit | edit source]

References

[edit | edit source]
  1. ↑ Apple Computer, Service Source: Macintosh Performa 400 Series — covers the Performa 400/405, 410, 430, 450, 460/466/467 and 475/476. Hosted on this wiki as File:Performa 400 series.pdf; see Macintosh Performa 400 Series Service Source.
  2. ↑ Doug Brown, “The capacitor that Apple soldered incorrectly at the factory”, 26 November 2024. Continuity and voltage measurements showing that C22 on the LC III board has its positive terminal on −5 V and its negative terminal on ground; comparison with the LC, LC II and LC 475 boards, which are wired the other way round; and the reported consequences of fitting a tantalum in the silkscreened orientation.
  3. ↑ Recap-a-Mac — Macintosh LC 475 / Quadra 605. Annotated photograph of the 820-0364-A logic board. Hosted on this wiki as File:Mac LC 475 Recap Guide.jpg. Secondary source.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Apple Computer, Service Source: Macintosh LC Series / Quadra 605 — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as File:Quadra 605.lc series.pdf; see Macintosh LC Series/ Quadra 605 Service Source.
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