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.

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:

IIvi/IIvx/Performa 600 Logic Board Capacitors

Capacitance	Voltage	Qty	Package	Recommended Replacement
47 µF	16V	6	SMD electrolytic	KEMET T491D476K016AT (tantalum)
220 µF	16V	2	Axial electrolytic	Vishay MAL213825221E3

Macintosh IIvi/IIvx logic board capacitor locations. Source: Recap-a-Mac

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).

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

1. Apply flux to capacitor terminals
2. Heat one terminal while gently tilting the capacitor
3. Alternate terminals until capacitor releases
4. Or use hot air at 350-380°C

Axial Capacitors

1. Heat one lead while applying gentle pressure
2. Remove solder with wick or pump
3. Repeat for second lead
4. Remove capacitor

Cleaning

After removal:

1. Remove all electrolyte residue with isopropyl alcohol
2. Inspect traces for corrosion
3. Check continuity on damaged-looking traces
4. 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

1. Tin one pad
2. Position capacitor (verify polarity)
3. Tack one terminal
4. Solder second terminal
5. Reflow first terminal
6. Clean flux residue

Testing

Before reassembly:

1. Visual inspection — verify all polarities
2. Continuity test — check for shorts
3. Power-on test — verify startup chime and operation

Purchasing Kits

Pre-made kits available from:

• Console5 (console5.com)
• Various eBay sellers

Related Pages

• Macintosh IIvx
• Macintosh IIvx General Maintenance
• Macintosh IIvx Troubleshooting
• Macintosh IIvi Capacitor Replacement Guide