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Recap guide

Recap the NeXT Computer and NeXTstation

SMD caps on the main board and in the power supply are known to fail, and a community list covers the lot.

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.

  • NeXT main logic board (Medium confidence). How to tell: Thread compiled lists for the NeXTcube; model of the board not stated. Capacitors: 6 SMD 47uF 16V and 4 through-hole 220uF 25V caps. Capacitor list differs from other revisions: not known. Source
  • NeXT power supply model 152.00 (Medium confidence). How to tell: Model number given in the thread; list taken from an early serial 030 machine so other serials may vary. Capacitors: About 14 positions from 0.47uF to 15000uF and 6.3V to 400V. Capacitor list differs from other revisions: not known. Source
  • MegaPixel display boards N4000 and N4000A (Low confidence). How to tell: Two board revisions named N4000 and N4000A. Capacitors: Separate analog and sound board lists exist for both; values not shown in the summary I read. 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.

  • Community cap lists (Medium confidence). A community thread lists 6 SMD and 4 through-hole caps on the main board and 14 in the PSU, plus the MO drive and MegaPixel analog and sound boards. 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: The 47uF 16V caps are the usual culprits (Medium confidence). In a NeXT capacitor list thread one technician says most NeXT machines show little leakage and it is usually enough to replace the 47uF 16V caps. The magneto-optical drive is the exception, where small leaked caps caused pin corrosion. Source
  • Watch out: Fit and heat traps on NeXT boards (Medium confidence). Posters say modern 1uF 50V caps for the MO drive can be about 3mm taller than the originals and may need tilting, and on the N4000 sound board an SMD cap sits so close to a connector that the connector was removed first to avoid melting it. The PSU also carries a lot of thermal compound on its heatsinks. Source
  • Story: Same can caps as the SE/30, not all leaked (Low confidence). On cctech a poster remarks the NeXTcube has the same SMT can caps as leaky Macs, while another notes not every one had spilled electrolyte, so inspect each machine rather than assume. Source

Before you start

  • Boards changed during production. Check your board number against the guides before you order parts.
  • A mains power supply can hold a dangerous charge. If you are not trained to work on one, have a professional do it.

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.

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