Macintosh IIvx Capacitor Replacement Guide: Difference between revisions
Added Capacitor_Replacement_Guides category |
Correct the '230 W power supply' (that is the Macintosh IIfx figure) to Apple's 200 W A/C line input and 112 W DC; warn that Apple's line input for this machine is 100-120 VAC and that the 100-240 V figure belongs to the switched monitor outlet, so the primary-side parts differ between mains variants; replace the generic discharge warning with the real hazard |
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== Power Supply Capacitors == | == Power Supply Capacitors == | ||
The IIvx | The IIvx supply is the shared desktop form factor also used in the IIci, IIcx, IIvi, Performa 600, Centris 650, and Quadra 700. Power supply capacitors vary by manufacturer (Sony, Astec, Delta).<ref>{{cite web |url=https://68kmla.org/forums/topic/59718-compact-desktop-power-supply-capacitor-lists-by-make-and-model/ |title=Compact Desktop Power Supply Capacitor Lists |publisher=68kMLA |access-date=2026-02-09}}</ref> | ||
Consult the specific power supply label for capacitor values. Common values include high-voltage primary capacitors (200V–400V) and secondary filter capacitors. | Consult the specific power supply label for capacitor values. Common values include high-voltage primary capacitors (200V–400V) and secondary filter capacitors. | ||
''' | '''Apple's own figures for this machine are 200 W at the A/C line input and 112 W of DC output'''<ref name="ssiivx">Apple Computer, ''Macintosh IIvx, Macintosh IIvi, Performa 600 Service Source'' ([[Macintosh IIvx Service Source]], [[:File:Macintosh_iivx.vi.perf_600.pdf]]), Specifications chapter and Additional Procedures → Battery Verification ("if the battery voltage is below 2.8 volts, replace the battery").</ref>; | ||
a "230 W" rating was previously given here and is the Macintosh IIfx's number. | |||
'''Check which mains variant you have before ordering primary-side parts.''' Apple prints the | |||
machine's A/C line input as '''100–120 VAC''' — the 100–240 VAC, 3 A figure often quoted for these | |||
machines is the rating of the '''switched monitor outlet''' on the back. A 220–240 V machine is a | |||
different supply, and a capacitor rated for rectified 120 V mains is not rated for rectified 240 V. | |||
'''Never fit a capacitor whose voltage rating is at or below the rail it sits on.''' | |||
'''The hazard, stated plainly.''' The primary reservoirs sit at the rectified mains potential and | |||
hold it after the unit is unplugged. Discharge them and '''verify with a meter''' before touching | |||
the board. Recapping a power supply is a normal repair; doing it with the reservoirs still charged | |||
is what kills people. | |||
== Tools Required == | == Tools Required == | ||
Revision as of 12:13, 27 September 2026
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 supply is the shared desktop form factor also used in 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.
Apple's own figures for this machine are 200 W at the A/C line input and 112 W of DC output[5]; a "230 W" rating was previously given here and is the Macintosh IIfx's number.
Check which mains variant you have before ordering primary-side parts. Apple prints the machine's A/C line input as 100–120 VAC — the 100–240 VAC, 3 A figure often quoted for these machines is the rating of the switched monitor outlet on the back. A 220–240 V machine is a different supply, and a capacitor rated for rectified 120 V mains is not rated for rectified 240 V. Never fit a capacitor whose voltage rating is at or below the rail it sits on.
The hazard, stated plainly. The primary reservoirs sit at the rectified mains potential and hold it after the unit is unplugged. Discharge them and verify with a meter before touching the board. Recapping a power supply is a normal repair; doing it with the reservoirs still charged is what kills people.
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
References
- ↑ Macintosh IIvi, Recap-a-Mac—link(accessed 2026-02-09)
- ↑ Macintosh IIvi, Recap-a-Mac—link(accessed 2026-02-09)
- ↑ Macintosh IIvx / IIvi / Performa 600 Cap Kit, Console5—link(accessed 2026-02-09)
- ↑ Compact Desktop Power Supply Capacitor Lists, 68kMLA—link(accessed 2026-02-09)
- ↑ Apple Computer, Macintosh IIvx, Macintosh IIvi, Performa 600 Service Source (Macintosh IIvx Service Source, File:Macintosh_iivx.vi.perf_600.pdf), Specifications chapter and Additional Procedures → Battery Verification ("if the battery voltage is below 2.8 volts, replace the battery").