RetroTechCollection

Macintosh LC 475 Capacitor Replacement Guide

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.

Symptoms of Capacitor Failure

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  • No audio or distorted audio
  • Boot failures or instability
  • Visible electrolyte leakage — Less common on LC 475 than earlier LCs
  • Corrosion on PCB traces

Capacitor List

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Logic Board Capacitors

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The LC 475 logic board contains fewer surface-mount electrolytic capacitors than earlier LC models.

Macintosh LC 475 Logic Board Capacitors
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
 
Macintosh LC 475/Quadra 605 logic board capacitor locations. Source: Recap-a-Mac

Note: The exact designators may vary. Consult a logic board diagram or use values from the existing capacitors.

Power Supply Capacitors

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Refer to the Macintosh LC Power Supply Recap Guide for PSU-specific information. The LC 475 uses a 30W power supply.

 
Macintosh LC power supply capacitor locations. Source: Recap-a-Mac

PRAM Battery Upgrade

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When recapping the LC 475, consider upgrading the PRAM battery holder:

  • Replace the original 1/2 AA battery holder with a CR2032 coin cell holder
  • CR2032 cells are widely available and easier to replace
  • Ensure correct voltage (3V for CR2032 vs. 3.6V for 1/2 AA)—this slight difference is acceptable

Capacitor Replacement Procedure

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Tools Required

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  • Temperature-controlled soldering iron (recommended: 300-350°C)
  • Fine tip for SMD work
  • Desoldering braid or solder wick
  • Flux (no-clean recommended)
  • Isopropyl alcohol (99%)
  • Soft brush (ESD-safe)
  • Multimeter
  • Replacement SMD electrolytic capacitors

Procedure

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

Important Notes

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  • Simpler recap — The LC 475 has fewer capacitors and is easier to work on than earlier LCs.
  • 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.
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External Resources

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