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Recap guide

Recap the Sun SPARCstation

SPARCstation power supplies have failed electrolytics and venting caps, and recap threads exist for the IPX and SS20.

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.

  • SPARCstation IPC and IPX supply (Medium confidence). How to tell: The IPC and IPX share the same power supply. Capacitors: Replacements fitted in an IPX: 470uF 25V, 3300uF 10V, 47uF 50V (some originals were 25V), 1uF 50V, 220uF 16V, 100uF 25V, 1000uF 25V. Capacitor list differs from other revisions: not known. Source
  • SPARCstation 20 supply FDK PEX668-31 (Medium confidence). How to tell: FDK part number as given on the forum. Capacitors: Output side caps C32, C35, C27, C29 fail first; the poster advises replacing all aluminum electrolytics with low impedance parts. 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.

  • IPX supply (Medium confidence). A DesignSpark write-up recaps the IPX supply and gives a parts list of seven values. Source
  • SS20 supply (Medium confidence). A thread on the SS20's FDK PEX668-31 supply has a Digi-Key parts list and a section on a failed attempt. 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: IPX PSU caps and the NVRAM battery (Medium confidence). A DesignSpark restoration of an IPX replaced the failed PSU electrolytics (a mix from 1uF 50V up to 3300uF 10V) and then dealt with the battery-backed NVRAM, which holds the MAC address and hostid. The author kept the historical MAC from system logs to reprogram the ID. Source
  • Watch out: SPARCstation 20 supply: C32, C35, C27, C29 (Medium confidence). A post on the FDK PEX668-31 supply names output filter caps C32, C35, C27 and C29 as venting with age, warns that the input caps can store a lethal charge, and says to use matched low-impedance parts. It also advises recording the EADDR and serial before the NVRAM battery dies. Source
  • Story: IPC: soft click, green LED flash, nothing (Medium confidence). A Sun IPC thread describes a supply that gives a soft click and a quick green LED flash, usually from the three tallest 3300uF caps leaking. The recommended parts were 105C low-ESR types such as Panasonic FR, with a thorough alcohol clean afterwards. 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

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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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