C:\>ConventionalMemory.io

Recap guide

Recap the Commodore 16 and Plus/4

Small boards with only a handful of electrolytics, plus kits. A popular fix also adds filtering and protection.

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

Check first. A recap is not always the answer here, so look at the guides before you order parts.

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.

  • C16 PCB 250443-01 rev A/B (Medium confidence). How to tell: Board number. Capacitors: Kit: 2x 1uF 50V, 6x 10uF 25V, 1x 47uF 16V, all radial. Capacitor list differs from other revisions: not known. Source
  • Plus/4 PCB 310163-01 (Medium confidence). How to tell: Board number. Capacitors: Kit: 1x 2200uF axial C7, 1x 1uF C23, 7x 10uF, 1x 100uF C1. Capacitor list differs from other revisions: not known. Source
  • Plus/4 PCB 250455 (Low confidence). How to tell: Board number. Capacitors: Same pack listed. 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.

  • Kit contents (Medium confidence). A kit seller shows what each pack contains for the C16 and Plus/4. Source
  • A mod, not a stock recap (Low confidence). One C16 write-up lists C2/C3/C4 changes and extra bulk caps, but it is a mod rather than a stock-value recap. Source
  • Heatsinks (Low confidence). One Plus/4 repair advocates replacing the old caps and adding heatsinks. 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.

  • Watch out: 7805 failure can leak input voltage (Medium confidence). A Plus/4 write-up warns the 7805 regulator can fail so its input leaks onto its output and damages the board, and suggests checking 9-12Vac unloaded in and 5.1-5.3Vdc unloaded out. The actual fault was a bad 4164 at U18, found with a diagnostic cartridge, even though all electrolytics were replaced with a Retroleum pack. Source
  • Tip: Check 5V at the bottom pins first (Low confidence). A forum answer on a black-screen Plus/4 says to measure 5V DC across the bottom two power connector pins (the upper pins carry 9V AC), looking for a steady 1 to 1.5A, then inspect for blown caps and burnt resistors. One reported fix combined an EPROM for the 317054-1 ROM, heatsinks and new electrolytics. Source
  • Tip: Original brick is not repairable (Low confidence). A hobbyist page calls the original Plus/4 power supply a non-repairable black brick and suggests a more reliable pack. It also says a power connector from a dead C64 board can be retrofitted so a C64 supply can be used. 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