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Power Macintosh 5260 Capacitor Replacement Guide

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Macintosh Performa 5260/120, the consumer version of the Power Macintosh 5260/120. Photo: Stephen Edmonds, Wikimedia Commons, CC BY-SA 2.5

Apple's service manual and developer note for the Power Macintosh 5260 give no capacitor list or schematic. The service manual for the 5260 and 5280 is module-level: Apple serviced these machines "through module exchange and parts replacements", and the manual's take-apart chapter treats the power supply, video board, analogue board and logic board as whole replaceable modules.[1] The only component designators it prints are adjustment controls, a few connectors, and U5, D1 and U12 on the optional MPEG card. Recap-a-Mac and MacDat, which publish annotated photographs of other Power Macintosh boards, have no page for the 5260 or 5280.[2] A recap therefore has to be done from the board itself.

The power supply and analogue board carry mains voltage and stored charge, and the CRT holds a high-voltage charge after power-off. Discharge the CRT before working near it; see CRT Discharge Procedure.

Boards and part numbers

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5260 and 5280 boards (Apple exploded view)
Module Apple part number
Logic board, 100 MHz 661-1116
Logic board, 120 MHz 661-1265
Power supply board 661-1133
Analogue/video board assembly 661-1134
CRT assembly 661-1135
Front panel control board 922-2182
TV tuner card 661-0160

Source: exploded view, p. 216.[1] These differ from the 5200 and 5300 boards, whose manual is titled "(not 5260, 5280)". The 5200 series has a 15-inch tube, and Apple's electrical specification for it is 125 W and 2.5 A maximum; the 5260 has a 14-inch tube, and its specification is 240 W and 4.0 A maximum (pp. 36, 42).[3][1] Do not order parts for a 5260 from a 5200 list.

Visual inspection

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Remove the I/O door and slide out the logic board to inspect it; the power supply, analogue board and video board need the rear housing, EMI shield and analogue shield off (pp. 91–140).[1] Look for the signs described in Capacitor Failure Symptoms: bulging or domed tops, electrolyte residue, corroded pads and a fishy smell. Check the area around the PRAM battery at the same time; it is a 4.5 V alkaline pack,[4] and alkaline leakage is caustic. See Battery Explosion, Capacitor or Corrosion Damage.

Apple's symptom charts route several faults to the analogue board: no start from the keyboard while the rear switch works, restarting after Shut Down, clicking or thumping noises, smoke or smell, and most picture faults (pp. 49, 53–58, 70).[1] Rule out the adjustments first: Apple says a misadjusted screen can mimic analogue board or CRT failure, and that some misconvergence at the screen edges is normal (pp. 47, 55). The charts are on Power Macintosh 5260 Troubleshooting.

Procedure

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  1. Photograph each board before removing anything, and record the value, voltage rating, polarity and position of every capacitor you intend to change.
  2. Discharge the CRT and let the supply stand unplugged before handling the power supply or analogue board.
  3. Fit replacements of the same capacitance and at least the same voltage rating. On the primary side of the power supply, rectified 230 V mains charges the reservoir to about 325 V (230 × √2), so a part rated below the original is dangerous.
  4. Refit the power supply connectors carefully. Apple says the power supply-to-analogue board connectors (P805, P804, P807) are keyed and fit snugly (p. 128).[1]
  5. Set the power supply before closing the case. Apple requires this adjustment whenever the analogue board or power supply has been taken out: DC voltmeter between the metal chassis and pin 3 of P805, adjust R828 for 110 V DC (pp. 213–214).[1]
  6. If the analogue board was worked on, do Apple's cutoff and white-balance procedure after a 10-minute warm-up (pp. 201–212).[1] The controls are listed in Power Macintosh 5260 General Maintenance.
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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Apple Computer, Service Source: Power Macintosh/Performa 5260, 5280 Series (1997), File:Powermac.perf 5260.5280.pdf; see Power Macintosh/Performa 5260, 5280 Series Service Source. Page numbers are PDF pages.
  2. ↑ Recap-a-Mac, recapping guides (its only Power Macintosh is the 6100), and MacDat, Power Macintosh and Performa capacitor references (no 5200, 5260 or 5280 entry), both read 12 October 2026.
  3. ↑ Apple Computer, Service Source: Power Macintosh/Performa 5200 and 5300 (not 5260, 5280) (1997), File:Powermac.perf 5200.5300.pdf, cover and Specifications pp. 40, 47 (PDF pages).
  4. ↑ Apple, "Power Macintosh 5260/100: Technical Specifications": battery type 4.5 V alkaline.
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