Editing PowerBook 2400c General Maintenance

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[[File:PowerBook 2400c-180 (Ray go).jpg|thumb|300px|PowerBook 2400c/180 (Ray_go, Wikimedia Commons, CC BY-SA 3.0)]]
Care and preventive work for the [[PowerBook 2400c]]. Apple's Service Source for this machine is short: it covers the battery, top case, palm rest, trackpad, keyboard, RAM card and I/O door, because Apple handled deeper repairs through its central repair depot.<ref name="ss24">Apple Computer, ''PowerBook 2400c'' Service Source (49 pp., 1997), hosted here as [[:File:PowerBook 2400c Service Source.pdf]] (see [[PowerBook 2400c Service Source]]). PDF page numbers: configuration and peripherals p. 4; service strategy pp. 5-6; battery information and handling pp. 15-17; PC Card handling pp. 18-19; electrical specifications p. 29; Battery pp. 33-34; Top Case pp. 35-36; Palm Rest pp. 37-39; Trackpad pp. 40-41; Keyboard pp. 42-44; RAM Card pp. 45-47; I/O Door pp. 48-49.</ref>

== Before opening the machine ==
* Unplug the adapter and remove the battery before any take-apart; refit the battery before reconnecting the adapter.<ref name="ss24" />
* The case screws are small Phillips screws; Apple uses a Phillips jeweller's screwdriver throughout, with a jeweller's flat blade for the latches.<ref name="ss24" />

== Batteries ==

=== Main battery ===
The 2400c uses its own lithium-ion battery (M5876LL/A), rated for 2-4 hours; Apple's specification page gives it as 29 Wh. NiMH packs and the [[PowerBook 3400c]] lithium-ion pack look similar but do not work in it.<ref name="ss24" /><ref name="sp173">Apple, [https://support.apple.com/kb/SP173 "Macintosh PowerBook 2400c/180: Technical Specifications"] (retrieved 2026-10-02). Battery type 29 Wh lithium-ion. </ref> To remove it, push the button and slide the battery out.<ref name="ss24" />

Apple's handling rules for the lithium-ion pack:<ref name="ss24" />
* Do not leave a battery in the computer for more than a week without the adapter connected.
* Keep the cap on a battery that is out of the computer, so the contacts are covered.
* Do not leave it somewhere hot, and do not store it for more than six months without recharging.
* Never get it wet or short its terminals; Apple warns a short can cause an explosion or fire.
* Recharge it only as the owner's manual describes, in a ventilated place.
For damaged or leaking packs, see [[Battery Explosion, Capacitor or Corrosion Damage]].

=== Backup battery ===
Apple describes the backup battery as a 30 mAh rechargeable lithium battery that keeps the clock, and the contents of RAM for a few minutes while the main battery is changed in sleep.<ref name="ss24" /> MacDat lists the 2400c among the laptops whose rechargeable NiCd or NiMH backup packs leak, and owners have found leakage on 2400c logic boards: one board was corroded along the battery wires and through two vias, another had a small leak cleaned up before the machine was used.<ref name="mdcmos">MacDat Knowledge Base, [https://www.macdat.net/repair/kb/batteries_laptops_cmos.php "Vintage Laptop CMOS Battery Leaks"] (retrieved 2026-10-02). NiCd and NiMH backup packs, usually Varta, that leak; Apple models listed: PowerBook 150, 2400c, 3400c. Secondary source.</ref><ref name="td4490">TinkerDifferent forum thread [https://tinkerdifferent.com/threads/powerbook-2400c-broken-glass-after-chime.4490/ "PowerBook 2400c - Broken Glass after chime"], Bama, July 2025. Corrosion from a leaking PRAM battery along its wires and in two vias. Community experience.</ref><ref name="td5343">TinkerDifferent forum thread [https://tinkerdifferent.com/threads/2400c-hard-drive-issues.5343/ "2400c hard drive issues"], mizerable, ClassicHasClass and Garrett, May 2026. A small PRAM battery leak cleaned by washing the board and soaking it in isopropyl alcohol; a broken IDE connector pin. Community experience.</ref> Apple's description and MacDat's list disagree on the chemistry; whichever is fitted, check it and remove it if it shows any sign of leaking. Clean corrosion off the board and connectors with isopropyl alcohol; see [[Battery Explosion, Capacitor or Corrosion Damage]].

== Power adapter ==
Use only the 2400c's own 36 W adapter (M5937LL/A). Apple's manual says other PowerBook adapters may damage the computer, and that the adapter should feel warm after ten minutes plugged in; a cold adapter is not connected or not working.<ref name="ss24" /><ref name="ug24">Apple Computer, ''Macintosh PowerBook 2400c User's Manual'' (1997), hosted here as [[:File:PowerBook 2400c User's Manual (1997).pdf]]. PDF page numbers: power sources and adapter warning (p. 80); start-up problems and resetting (pp. 89-90); PRAM reset (pp. 90-91); restart and reset (p. 93); the display lighting then shutting down (p. 94); floppy disk (p. 101); trackpad (p. 103); display flicker (p. 104).</ref>

== Resetting the computer ==
Apple's order, from the owner's manual:<ref name="ug24" />
# Press Command, Control and the power key together.
# If that does not work, connect the adapter and press the reset button on the back panel. A steady green sleep light in the display latch always needs the reset button.
# After a reset the computer tests its RAM, at about one second per megabyte, before the screen lights.
# To reset PRAM, which also resets the power manager: restart, and straight after the startup sound hold Command, Option, P and R until the startup sound plays again. Resetting PRAM clears any RAM disk and most control panel settings.

== Opening the case ==
=== Top case ===
Remove the battery, then the two Phillips screws from the top case. Release the two front latches with a jeweller's flat blade and lift the top case off. Apple warns that the left side may need some pressure, and that the display cable lies directly beneath it and can be torn.<ref name="ss24" />

=== Palm rest and trackpad ===
Lift off the hinge cover. The palm rest stays connected by the trackpad cable, so do not raise it more than an inch above the keyboard until the cable is off. Hold it by the battery bay and the upper left corner, slide it forward, lift it to free its latches, rotate it towards you, release the locking tab and unplug the trackpad cable from the logic board.<ref name="ss24" /> The trackpad itself is held in the palm rest by a holder with two screws.<ref name="ss24" /> Apple's advice for a pointer that sticks or jumps is to use one dry finger on the pad.<ref name="ug24" />

=== Keyboard ===
With the top case and palm rest off, remove the six keyboard screws, slide the keyboard forward an inch to reach its two connectors, release their locking tabs and unplug the cables. When refitting, tuck the loops of the keyboard cables under the back structure.<ref name="ss24" />

=== RAM card ===
The RAM card sits under an EMI shield held by two screws, below the keyboard. Hold the card by its edges, never by the chips, and release the two latches on the sides of the connector to remove it.<ref name="ss24" /> The Service Source mentions third-party cards of 16 MB and 32 MB; see [[PowerBook 2400c#Specifications|PowerBook 2400c]] for the conflicting maximum memory figures.<ref name="ss24" />

== Storage ==
The internal drive is a 2.5-inch ATA (IDE) disk.<ref name="sp173" /> If a 2400c boots from an external SCSI disk but sees no internal drive, check the IDE connector on the logic board: one owner found a broken pin and repaired it with a bodge wire.<ref name="td5343" /> Low End Mac warns that the drive controller in pre-G4 PowerBooks does not work with ATA-6 (Ultra ATA/100) drives.<ref name="lem2400">Low End Mac, [https://lowendmac.com/1997/powerbook-2400c/ "PowerBook 2400c"] (retrieved 2026-10-02). ATA-6 drive warning; Password Security and Mac OS 8. Secondary source.</ref> See [[Hard Drive Maintenance and Repair]].

The external floppy drive (M5853LL/A) has its own connector and removable cable and does not fit other PowerBooks.<ref name="ss24" /> To free a stuck disk, restart holding the trackpad button, or push a straightened paper clip into the hole beside the slot.<ref name="ug24" />

== Capacitors ==
Elemenoh reported that the 2400's logic board uses tantalum capacitors and listed eight through-hole capacitors on its power and I/O board; starlite, who maintains MacDat's capacitor lists, identified these as Sanyo OS-CON solid-polymer parts, which do not leak and very rarely fail.<ref name="td2605">TinkerDifferent forum thread [https://tinkerdifferent.com/threads/powerbook-2400-power-io-board-capacitors.2605/ "PowerBook 2400 Power/IO board capacitors"], Elemenoh and starlite, May 2023. Values, sizes and positions of the power/IO board capacitors; their identification as Sanyo OS-CON solid polymer; no information yet on the display or inverter board. Community experience.</ref> The values are kept here for reference:

{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+ '''PowerBook 2400 power/IO board capacitors (Elemenoh)'''<ref name="td2605" />
! Position !! Value !! Voltage !! Diameter × height !! Temperature
|-
| C15 || 33 µF || 25 V || 10 × 10.5 mm || 105 °C
|-
| C25 || 10 µF || 30 V || 8 × 10.5 mm || 105 °C
|-
| C26 || 10 µF || 30 V || 8 × 10.5 mm || 105 °C
|-
| C38 || 220 µF || 10 V || 10 × 10.5 mm || 105 °C
|-
| C39 || 100 µF || 10 V || 10 × 6 mm || 105 °C
|-
| C46 || 330 µF || 6.3 V || 10 × 10.5 mm || 105 °C
|-
| C47 || 150 µF || 6.3 V || 10 × 6 mm || 105 °C
|-
| C48 || 100 µF || 10 V || 10 × 6 mm || 105 °C
|}

Nobody in that thread had values for the 2400c's display or inverter board; starlite asked for them.<ref name="td2605" />

== Preventive checklist ==
# Remove the backup battery, or at least inspect it and the board around its wires for leakage.
# Check the main battery for swelling or damage before charging it, and keep its cap on when it is out.
# Use only the 36 W 2400c adapter.
# Take care with the display cable under the left side of the top case whenever the case is opened.
# Back up or replace the original hard disk.

== Related pages ==
* [[PowerBook 2400c]]
* [[PowerBook 2400c Troubleshooting]]
* [[PowerBook 2400c Service Source]]
* [[Battery Refurbishment]]

== References ==
<references />

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