C:\>ConventionalMemory.io

Recap guide

Recap the PowerBook 100 to 500

Early PowerBooks have leaky electrolytics on the logic board and LCD boards, and the PowerBook 100 has the best documentation.

Open the interactive checklist Tick off each capacitor as you replace it. It saves in your browser.

Worth a recap. Reports say it is a common and useful fix on this machine.

Which board do I have?

Boards changed during production. These notes come from the linked sources, and many are only partly documented, so check the board in front of you.

  • PowerBook 100 (Low confidence). How to tell: Labelled PowerBook 100 on the case. Capacitors: Eight electrolytics on the back of the LCD panel and two caps near the display connector on the logic board are the known failures; one poster used 33uF 16V on the LCD panel. Capacitor list differs from other revisions: not known. Source

Where to start

Clues from write-ups and forum threads, not a diagnosis. Low confidence means one thread or one repair; high means several write-ups agree.

  • Dark LCD (PowerBook 100) (Medium confidence). One fix for a dark LCD replaces eight caps behind the screen, with values given, plus two on the logic board. Source
  • Detailed repair story (Medium confidence). A Gough's Tech Zone repair walks through test and replace, with a tantalum swap and LCD and inverter board findings. Source
  • Other models (Low confidence). A July 1994 Apple service guide covers the PowerBook 520/540 and Duo models with parts lists, but has no cap list. Source

Tips, tales and maybes

Found in write-ups and forum threads. These are other people's reports, not tested by us. Check part references and values against your own board.

  • Tip: PowerBook 100 screen recap parts and inductors (Medium confidence). A thread on the 100 display board suggests 3.3uF 35V parts (tantalum size B, or MLCC which fits better) and says to remove and inspect all three 150uH inductors, particularly L3, since leakage often corrodes their connections and can stop the display entirely. Source
  • Story: PowerBook 100 restore notes (Low confidence). One PowerBook 100 restoration found the 47uF caps smelling of leak, noted missing audio caps mean no sound, and had a delay from copying a cap list wrong. The Conner drive trouble came from rubber bumpers turning to goo, which is separate from the capacitors. Source
  • Story: 170 PSU collapsing to 1.1V (Low confidence). A PowerBook 170 with no chime and the supply voltage falling to 1.1V instead of about 7.5V was blamed on failed PSU electrolytics, with a reply predicting leakage under them. Advice included reflowing the PSU board and testing with the hard drive disconnected. Source
  • Tip: Recap the old adapter too (Low confidence). A bench test of Portable and PowerBook 100 adapters found worn caps cause voltage sag and leakage that eats traces. One adapter measured 7.0V at 1.0A before recapping and 7.25V after. Treat adapters as part of the recap job. Source

Before you start

  • Boards changed during production. Check your board number against the guides before you order parts.

Guides we used

This page and the interactive bench are built from these. They have the photos and the full detail, so please read them and support their authors.

The capacitor list

We have not checked a capacitor list for this machine yet, so none is shown. Follow the guide above for your board, then add the capacitors in the interactive checklist and it builds a shopping list for you.

Skip the sourcing

While you are in there

Affiliate links. As an Amazon Associate I earn from qualifying purchases. These links only search by name. Disclosure

Steps, tools and safety

The steps, the tools in top, middle and budget picks, and the safety list are the same for every machine, so they live on one page: How to recap, step by step.

Values are shown as published in the guides above, and boards changed during production. Check the board in front of you. A recap involves hot tools and, on some machines, dangerous voltages. You do it at your own risk.

More