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Macintosh IIvx Capacitor Replacement Guide

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Revision as of 16:14, 30 September 2026 by Josh (talk | contribs) (Rewrite: Recap-a-Mac values and parts, Console5 kit, Macworld same-board source; Apple take-apart steps; PSU is 661-0758, list on Centris 650 guide; remove 68kMLA shared-form-factor claim (IIci/IIcx/Q700 do not use this supply), 100-120 V different-supply claim, generic procedure padding and tombstoned category)
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The logic board of the Macintosh IIvx has eight aluminium electrolytic capacitors, and Recap-a-Mac notes that the IIvi is not "immune from leaky capacitors and exploding batteries".[1] Apple built the IIvx, IIvi and Performa 600 on the same basic logic board, the IIvx adding the FPU and cache, and Console5 sells one logic board capacitor kit for all three.[2][3] Apple published no capacitor list for these boards.

Signs of failure

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  • Residue or corrosion around the surface-mount capacitors and on nearby pads.
  • A leaking battery does similar damage; on the board Recap-a-Mac photographed, the holder (BT1) and the area around it were destroyed.[1]
  • For the symptoms of failed capacitors see Capacitor Failure Symptoms; for Apple's fault charts see Macintosh IIvx Troubleshooting.

Logic board capacitor list

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Macintosh IIvi logic board 820-0373-A with the electrolytic capacitors marked (Recap-a-Mac)
IIvx / IIvi / Performa 600 logic board
Quantity Value Type Where Replacement used by Recap-a-Mac
6 47 µF 16 V Surface-mount electrolytic Two beside the SCSI and floppy connectors; four along the left edge near the ports KEMET T491D476K016AT tantalum
2 220 µF 16 V Axial electrolytic Near the power connector at the top of the board Vishay MAL213825221E3

Values and positions are from Recap-a-Mac's photograph of a IIvi board.[1] A higher voltage rating in the same size is acceptable. On a tantalum the bar marks the positive end, the opposite of an aluminium electrolytic.[3]

Power supply

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The supply is Apple part 661-0758, shared with the Macintosh Centris 650 and Quadra 650.[4][5] Its capacitor list and the warning about its primary reservoir pair are on the Macintosh Centris 650 Capacitor Replacement Guide. Apple's ratings for it are on Macintosh IIvx General Maintenance.

The supply works from rectified mains and its reservoir capacitors hold a charge after it is unplugged. Discharge them and confirm with a meter before working on the primary side.

Procedure

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Apple's take-apart order is top cover, power supply, internal chassis, reset/interrupt switch and speaker, then the logic board.[4]

  1. Loosen the captive screw at the rear, slide the top cover forward about an inch and lift it off.[4]
  2. If a CD-ROM drive is fitted, squeeze its side tabs and pull it forward an inch or two. Remove the screw from the rear bezel, prise the latch away from the base of the power supply, and lift the supply firmly out.[4]
  3. Disconnect the floppy, SCSI power and SCSI data cables (and the CD-ROM cables if fitted), remove the two screws holding the internal chassis, swing its front up until it is vertical and lift its tabs out of the bottom case.[4]
  4. Lift the centre tab of the reset/interrupt switch and ease the switch up and away from the front of the case. Disconnect the speaker cable from the logic board and remove the speaker's screws.[4]
  5. Remove the screw in the centre of the logic board, slide the board forward about half an inch and lift it out.[4]
  6. Photograph the board and note the polarity of every capacitor. Remove the old parts, clean off any electrolyte, check the pads and tracks, and fit the new capacitors observing polarity.
  7. Refit the board by placing the centre of its rear edge in the plastic bracket and sliding it straight back, and seat the internal chassis's bottom corners in the guides in the case.[4]
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References

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  1. ↑ 1.0 1.1 1.2 Macintosh IIvi, Recap-a-Mac—link(accessed 2026-09-30) Annotated photograph of Macintosh IIvi logic board 820-0373-A, hosted here as File:Mac IIvi Recap Guide.jpg: 6 × 47 µF 16 V surface-mount, 2 × 220 µF 16 V axial; replacement parts KEMET T491D476K016AT (47 µF 16 V tantalum) and Vishay MAL213825221E3 (220 µF 16 V axial).
  2. ↑ Charles Seiter, "Macintosh IIvx", Macworld, December 1992, pp. 206-207, archive.org: the IIvx has "the same case, the same basic logic board" as the Performa 600.
  3. ↑ 3.0 3.1 Macintosh IIvx / IIvi / Performa 600 SMD Tantalum and Axial Main PCB Cap Kit, Console5—link(accessed 2026-09-30) Surface-mount tantalum and axial electrolytic kit for IIvx, IIvi and Performa logic boards; the marking bar on a tantalum indicates the positive side.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Apple Computer, Macintosh IIvx, Macintosh IIvi, Performa 600 Service Source, File:Macintosh iivx.vi.perf 600.pdf; see Macintosh IIvx/IIvi/Performa 600 Service Source. Take Apart, PDF pp. 26-51: top cover p. 26; power supply pp. 27-29; internal chassis pp. 30-36; speaker pp. 47-48; logic board pp. 49-51. Exploded View p. 76.
  5. ↑ Quadra 650, IIvi, IIvx, Power Mac 7100, Performa 600 – Power Supply, Apple Rescue of Denver—link(accessed 2026-09-30) Apple 614-0009, 661-0758, 112 W; Delta SMP-120EB or Astec AA16870.


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