Macintosh IIvx Capacitor Replacement Guide
The Macintosh IIvx logic board contains surface-mount electrolytic capacitors that leak after 30+ years. This guide provides capacitor specifications and replacement procedures.
The IIvx, Macintosh IIvi, and Performa 600 share the same logic board design, so capacitor specifications are identical.[1]
Why Recap?
Electrolytic capacitors contain liquid or gel electrolyte that leaks over time. The leaked electrolyte is:
- Conductive — creates short circuits between traces
- Corrosive — destroys copper traces and attacks solder joints
Proactive recapping prevents irreversible damage.
Logic Board Capacitors
The IIvi/IIvx/Performa 600 logic board contains SMD electrolytic and axial capacitors:[2][3]
| Capacitance | Voltage | Qty | Package | Recommended Replacement |
|---|---|---|---|---|
| 47 µF | 16V | 6 | SMD electrolytic | KEMET T491D476K016AT (tantalum) |
| 220 µF | 16V | 2 | Axial electrolytic | Vishay MAL213825221E3 |
Replacement Options
Tantalum (recommended for SMD):
- Solid electrolyte — cannot leak
- Available from Mouser, Digi-Key
- Note: stripe marks positive terminal (opposite of electrolytic)
Axial electrolytic:
- Use 105°C rated, low-ESR types
- Match original footprint
- Stripe marks negative terminal
Power Supply Capacitors
The IIvx uses a 230W power supply shared with the IIci, IIcx, IIvi, Performa 600, Centris 650, and Quadra 700. Power supply capacitors vary by manufacturer (Sony, Astec, Delta).[4]
Consult the specific power supply label for capacitor values. Common values include high-voltage primary capacitors (200V–400V) and secondary filter capacitors.
Warning: Power supplies contain high-voltage capacitors. Discharge before servicing.
Tools Required
- Soldering iron with fine tip (for SMD) and chisel tip (for axial)
- Hot air rework station (optional but helpful for SMD)
- Solder (60/40 or 63/37, 0.5-0.8mm)
- Flux (no-clean or rosin)
- Solder wick and desoldering pump
- Isopropyl alcohol (>90%) and brushes
- Multimeter
- Safety glasses
Removal Procedure
SMD Capacitors
- Apply flux to capacitor terminals
- Heat one terminal while gently tilting the capacitor
- Alternate terminals until capacitor releases
- Or use hot air at 350-380°C
Axial Capacitors
- Heat one lead while applying gentle pressure
- Remove solder with wick or pump
- Repeat for second lead
- Remove capacitor
Cleaning
After removal:
- Remove all electrolyte residue with isopropyl alcohol
- Inspect traces for corrosion
- Check continuity on damaged-looking traces
- Repair with conductive pen or jumper wire if needed
Installation
Polarity
Critical: Capacitors are polarized. Installing backwards causes:
- Electrolytic: bulging, popping, or fire
- Tantalum: short circuit, fire
SMD electrolytic: stripe marks negative Tantalum: stripe marks positive Axial electrolytic: stripe marks negative
Soldering
- Tin one pad
- Position capacitor (verify polarity)
- Tack one terminal
- Solder second terminal
- Reflow first terminal
- Clean flux residue
Testing
Before reassembly:
- Visual inspection — verify all polarities
- Continuity test — check for shorts
- Power-on test — verify startup chime and operation
Purchasing Kits
Pre-made kits available from:
- Console5 (console5.com)
- Various eBay sellers