PowerBook 540 Capacitor Replacement Guide

Capacitor values for the PowerBook 500 series: the PowerBook 520, 520c, PowerBook 540 and 540c, and their M1893 power adapter. The motherboard has a single electrolytic. Most of the electrolytics are on the display boards, which differ by model, and on the backlight inverter board, which all four share.^[1] Apple published no component-level parts list for these machines; the Service Source works at module level, so the values below come from MacDat's capacitor reference, compiled from boards and photographs.^[2]

Signs of trouble

For a backlight that does not light, Apple's chart replaces the inverter board before the display.^[2] An owner of two 540s reports few capacitors on the main board and some on the inverter board that can leak.^[3]
MacDat's view: most 540s run without a recap, but replace at least the one motherboard capacitor; on a 520c, recap both the display and the motherboard.^[1]^[4]
An adapter that measures low or nothing on pins 1 and 2 (Apple gives 16.4-16.6 V) needs opening.^[2]^[5]

See Capacitor Failure Symptoms for general signs.

Capacitor lists

MacDat's counts are per board. Positions are shown on the photographs linked from each table; MacDat does not give designators for the computer's boards.

Motherboard (all models)

**PowerBook 500 series motherboard**^[1]
Value	Voltage	Count	Type
100 µF	25 V	1	Surface-mount electrolytic

Backlight inverter board (all models)

**PowerBook 500 series inverter board**^[1]
Value	Voltage	Count	Type	Notes
220 µF	6.3 V	1	Low-profile radial electrolytic
22 µF	6.3 V	1	Low-profile radial polymer	MacDat: polymer parts very rarely fail; replace only if you want to
6.8 µF	25 V	2	Low-profile radial polymer	As above

Display boards

**PowerBook 520: Sharp LM64P858 panel**^[6]
Value	Voltage	Count	Type
3.3 µF	35 V	8	Low-profile surface-mount electrolytic
10 µF	16 V	1	Low-profile surface-mount electrolytic

**PowerBook 520c: Sharp LM64C12P panel**^[4]
Value	Voltage	Count	Type
10 µF	50 V	6	Low-profile radial electrolytic

**PowerBook 540c: Sharp LQ94D041 panel**^[7]
Value	Voltage	Count	Type
100 µF	6 V	3	Surface-mount electrolytic
47 µF	16 V	1	Surface-mount electrolytic
47 µF	6 V	6	Surface-mount electrolytic
33 µF	10 V	1	Surface-mount electrolytic
22 µF	10 V	1	Surface-mount electrolytic
10 µF	25 V	1	Surface-mount electrolytic

The 540c was built with Sharp, Toshiba or Hosiden panels. MacDat's list applies to the Sharp panel only; it says the Toshiba panel also uses electrolytics and believes the Hosiden panel is solid state.^[7] Identify the panel before ordering parts. MacDat lists no display capacitors for the greyscale 540.^[1]

520, Sharp LM64P858: red 3.3 µF 35 V, cyan 10 µF 16 V
520c, Sharp LM64C12P: six 10 µF 50 V
540c, Sharp LQ94D041, original values labelled

Power adapter (M1893)

**PowerBook 500 series AC adapter**^[5]
Designator	Value	Voltage	Size (diameter × height)	Type
C1, C2	100 µF	200 V	16 × 26 mm	Radial
C308A, C308B	330 µF	25 V	8 × 20 mm	Radial
C14A, C14B	100 µF	25 V	6 × 11 mm	Radial
C802	47 µF	25 V	5 × 11 mm	Radial

Warning: C1 and C2 are the 200 V capacitors on the mains side of the adapter and can hold a dangerous charge after it is unplugged. Discharge them and check with a meter before touching the board.

Replacement procedure

Inverter board

Remove the battery or PCMCIA module, the clutch covers and the display access cover, then the display assembly: support it from beneath, disconnect the interconnect-to-logic-board cable, remove the two T-8 screws and slide it left until the right clutch clears the cable loop.^[2]
Remove the display bezel: take the microphone out of its retainer, unplug the speaker cable from the interconnect board, remove the bottom two bezel screws, prise off the two rubber bumpers, remove the top two screws, and pull the bezel forward off its two hooks on each side.^[2]
Remove the inverter board's two screws, unplug the interconnect-to-inverter cable and the backlight cable, and lift the board out.^[2]
Replace the 220 µF 6.3 V electrolytic, and the polymer parts if you choose. MacDat lists all four as low-profile radial parts.^[1]

Display boards

With the bezel off, the display comes out after its four mounting screws are removed and the backlight and interconnect-to-display cables are unplugged.^[2] MacDat advises against replacing the display capacitors with ceramics, which can make the contrast drift because their capacitance changes with applied voltage, and recommends tantalum parts instead.^[6]

Motherboard

The motherboard capacitor needs the most dismantling. Apple's motherboard removal comes after the battery or module, clutch covers, display access cover, display assembly, keyboard, hard drive, centre base cover, floppy drive, daughterboard EMI shield, top case, interconnect-to-logic-board cable, CPU stiffener and DAA card. Then remove the mounting screw and standoff, ease the board off its positioning peg, slide it forward a quarter of an inch and lift it, keeping the sound jacks clear of the rear panel.^[2] When lifting the top case, remember the trackpad cable still joins it to the motherboard.^[2]

Tools and parts

T-8 and T-6 Torx drivers, a small flat-blade screwdriver and an IC extractor bent out to a wide grip for the daughterboard.^[2]
A fine-tipped iron or hot-air station for the surface-mount parts, flux, and isopropyl alcohol to clean off old electrolyte.
Low-profile replacement parts for the inverter and display boards; see Recommended Tools.

After the recap

Check the backlight lights evenly and adjusts with the brightness control.
Check the adapter at pins 1 and 2: 16.4-16.6 V.^[2]
Run the machine on battery and on the adapter; if it runs only on the adapter with a good battery, see PowerBook 540 Troubleshooting.

Related pages

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 MacDat Capacitor Reference Library, "PowerBook 540 Capacitor Reference" (retrieved 2026-10-02). Logic board: one 100 µF 25 V surface-mount electrolytic; inverter board: one 220 µF 6.3 V low-profile radial electrolytic, one 22 µF 6.3 V and two 6.8 µF 25 V low-profile radial polymer capacitors that "very rarely fail". No display capacitors listed for the 540. Logic board photograph credited to AEChadwick. Secondary source.
↑ ^2.00 ^2.01 ^2.02 ^2.03 ^2.04 ^2.05 ^2.06 ^2.07 ^2.08 ^2.09 ^2.10 Apple Computer, PowerBook 500 Series Service Source (180 pp., this copy last modified July 2002), hosted here as File:PowerBook 500 Series Service Source.pdf (see PowerBook 500 Series Service Source). Module-level only. PDF page numbers: Battery/PCMCIA Module pp. 64-67; Keyboard pp. 68-71; Clutch Covers pp. 76-78; Display Access Cover pp. 79-80; Display Assembly pp. 81-83; Top Case pp. 100-104; Motherboard pp. 116-119; Display Bezel Assembly pp. 136-139; Display pp. 140-142; Inverter Board pp. 143-144; exploded view p. 180.
↑ TinkerDifferent forum thread "Powerbook 540C with powerPC, What now?", clay, September 2026. Few capacitors on the 540 main board; inverter board capacitors that can leak. Community experience.
↑ ^4.0 ^4.1 MacDat Capacitor Reference Library, "PowerBook 520c Capacitor Reference" (retrieved 2026-10-02). Sharp LM64C12P display: six 10 µF 50 V low-profile radial electrolytics; MacDat recommends recapping both the display and the logic board on a 520c. Display image credited to techknight. Secondary source.
↑ ^5.0 ^5.1 MacDat Capacitor Reference Library, "PowerBook 500 Series AC Adapter" (retrieved 2026-10-02). Capacitor list with sizes; photograph and annotation by Fizzbinn (68kMLA), used with permission; opening the case; adapters that failed after a recap. Secondary source.
↑ ^6.0 ^6.1 MacDat Capacitor Reference Library, "PowerBook 520 Capacitor Reference" (retrieved 2026-10-02). Sharp LM64P858 display: eight 3.3 µF 35 V and one 10 µF 16 V low-profile surface-mount electrolytics; advice against ceramic replacements; logic board and inverter as the 540. Display photograph credited to oldcrap.org. Secondary source.
↑ ^7.0 ^7.1 MacDat Capacitor Reference Library, "PowerBook 540c Capacitor Reference" (retrieved 2026-10-02). The 540c shipped with a Sharp, Toshiba or Hosiden panel; Sharp and Toshiba panels use electrolytics, the Hosiden is believed to be solid state; list for the Sharp LQ94D041 only. Photograph credited to jmacz. Secondary source.

[md540-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 MacDat Capacitor Reference Library, "PowerBook 540 Capacitor Reference" (retrieved 2026-10-02). Logic board: one 100 µF 25 V surface-mount electrolytic; inverter board: one 220 µF 6.3 V low-profile radial electrolytic, one 22 µF 6.3 V and two 6.8 µF 25 V low-profile radial polymer capacitors that "very rarely fail". No display capacitors listed for the 540. Logic board photograph credited to AEChadwick. Secondary source.

[ss5-2] 2.00 ^2.01 ^2.02 ^2.03 ^2.04 ^2.05 ^2.06 ^2.07 ^2.08 ^2.09 ^2.10 Apple Computer, PowerBook 500 Series Service Source (180 pp., this copy last modified July 2002), hosted here as File:PowerBook 500 Series Service Source.pdf (see PowerBook 500 Series Service Source). Module-level only. PDF page numbers: Battery/PCMCIA Module pp. 64-67; Keyboard pp. 68-71; Clutch Covers pp. 76-78; Display Access Cover pp. 79-80; Display Assembly pp. 81-83; Top Case pp. 100-104; Motherboard pp. 116-119; Display Bezel Assembly pp. 136-139; Display pp. 140-142; Inverter Board pp. 143-144; exploded view p. 180.

[td5607-3] TinkerDifferent forum thread "Powerbook 540C with powerPC, What now?", clay, September 2026. Few capacitors on the 540 main board; inverter board capacitors that can leak. Community experience.

[md520c-4] 4.0 ^4.1 MacDat Capacitor Reference Library, "PowerBook 520c Capacitor Reference" (retrieved 2026-10-02). Sharp LM64C12P display: six 10 µF 50 V low-profile radial electrolytics; MacDat recommends recapping both the display and the logic board on a 520c. Display image credited to techknight. Secondary source.

[md500ac-5] 5.0 ^5.1 MacDat Capacitor Reference Library, "PowerBook 500 Series AC Adapter" (retrieved 2026-10-02). Capacitor list with sizes; photograph and annotation by Fizzbinn (68kMLA), used with permission; opening the case; adapters that failed after a recap. Secondary source.

[md520-6] 6.0 ^6.1 MacDat Capacitor Reference Library, "PowerBook 520 Capacitor Reference" (retrieved 2026-10-02). Sharp LM64P858 display: eight 3.3 µF 35 V and one 10 µF 16 V low-profile surface-mount electrolytics; advice against ceramic replacements; logic board and inverter as the 540. Display photograph credited to oldcrap.org. Secondary source.

[md540c-7] 7.0 ^7.1 MacDat Capacitor Reference Library, "PowerBook 540c Capacitor Reference" (retrieved 2026-10-02). The 540c shipped with a Sharp, Toshiba or Hosiden panel; Sharp and Toshiba panels use electrolytics, the Hosiden is believed to be solid state; list for the Sharp LQ94D041 only. Photograph credited to jmacz. Secondary source.

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