Editing Apple PowerBook power adapters (section)

== PowerBook 500 series ==
The PowerBook 500 series adapter, M1910, is rated at 40 W and is two 20 W supplies in one case: Vbatt gives 16.6 V at 1.0 A and Vmain 16.6 V at 1.5 A, from 100–240 V AC at 50–60 Hz. With the computer off or asleep both outputs charge the batteries, which takes two hours for two flat batteries; with the computer running, Vmain powers it and Vbatt charges one battery and then the other, four hours in all.<ref name="til16168" /><ref name="til15664">Apple Computer, Tech Info Library article 15664, ''PowerBook 500 Series AC Adapter Ratings (6/94)'', [http://absurdengineering.org/library/MASTER%20Tech%20Info%20Library/Macintosh%20Hardware/Macintosh%20PowerBook%20Family/PowerBook%20500%20Series/TIL15664%20-%20PowerBook%20500%20Series%20AC%20Adapter%20Ratings%20%286-94%29.pdf absurdengineering.org library]. 40 W; Vbatt 16.6 V 1.0 A and Vmain 16.6 V 1.5 A; 100–240 V AC input; charging times.</ref>

To test it, use narrow probes in the four numbered holes of the plug, with the negative lead on the outer shield, which is ground:<ref name="til16680" />
{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''500 series adapter connector (Apple Tech Info Library 16680)'''<ref name="til16680" />
! Hole !! Signal !! Reading
|-
| 1 || Vbatt || 16.4–16.6 V
|-
| 2 || Vmain || 16.4–16.6 V
|-
| 3 || Ground || 0 V
|-
| 4 || Ground sense || 0 V
|}
MacDat calls these adapters very unreliable: its author recapped two that had leaked, and both worked briefly and then died again. The brittle case cannot be opened without damage; MacDat's method is to squeeze it in a vice with a pencil either side of the seam. Its fallback is to run the PowerBook from a modern 16 V supply.<ref name="macdat500">MacDat Capacitor Reference Library, "PowerBook 500 Series AC Adapter", https://macdat.net/repair/cap_reference/apple/powerbook/500_ac.php (read 4 October 2026). Reliability, opening the case, capacitor list with sizes, photograph from Fizzbinn.</ref>
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''PowerBook 500 series adapter electrolytics (MacDat, community source)'''<ref name="macdat500" />
! Positions !! Value !! Size (D × H, mm)
|-
| C1, C2 || 100 µF 200 V || 16 × 26
|-
| C308A, C308B || 330 µF 25 V || 8 × 20
|-
| C14A, C14B || 100 µF 25 V || 6 × 11
|-
| C802 || 47 µF 25 V || 5 × 11
|}
[[File:PowerBook 500 Series M1893 AC adapter capacitor map (MacDat).jpg|thumb|center|450px|A PowerBook 500 series adapter opened, with its capacitors marked (Fizzbinn, via MacDat)]]