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Recap guide

Recap the Macintosh SE/30

The SE/30 is a legend, and its surface mount logic board capacitors are famous for leaking. Replacing them now saves the board.

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

Difficulty: Careful

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.

  • SE/30 logic board (no revision split found) (Medium confidence). How to tell: No readable source separates SE/30 logic board revisions, so identify by what is on the board: surface mount 47uF parts plus two large axial caps. Capacitors: One write-up counts 1x 1uF 50V SMD, 10x 47uF 16V SMD, 1x 220uF 16V axial and 1x 470uF 16V axial on the logic board. A UK recap shop says its SE/30 service covers all board revisions, swapping SMD parts for polymer and the two axials for standard electrolytics. Capacitor list differs from other revisions: not known. Source
  • SE/30 power supply, Sony made (Low confidence). How to tell: Check the maker named on the supply; a Tinker Different thread only says stock supplies were made by Sony or Astec. Capacitors: No capacitor values in that thread and no statement on whether the Sony and Astec units differ inside. Modern drop-in replacements are mentioned as an alternative to recapping. Capacitor list differs from other revisions: not known. Source
  • SE/30 power supply, Astec made (Low confidence). How to tell: Check the maker named on the supply; stock units were Astec or Sony according to the same thread. Capacitors: No capacitor values for the Astec unit in the source I could 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.

  • Very quiet sound (Low confidence). In one Tinker Different thread, a very quiet SE/30 was fixed right away by replacing C3 to C6, a square group near the Sony audio chips. A reply called it a very common SE/30 problem and advised replacing them all eventually. Source
  • Scrambled video or scan lines after a recap (Low confidence). Leaked electrolyte can eat traces. Several posters had scrambled video or bright scan lines after recapping. The advice was to clean with alcohol and a soft brush and check the pins and traces near UD8 and UE8. In another case, a horizontal-line fault pointed to the analog board. Source
  • Leaks you cannot see (Low confidence). One thread found caps that looked fine from above but had leaked underneath. The consensus there was to replace all the electrolytic and tantalum capacitors. 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.

  • Story: Bright horizontal line was not the recap (Medium confidence). An SE/30 with a flickering bright horizontal line and crackling speaker had the video fault before the recap. Replies blamed cracked analog board solder joints and advised reflowing them and checking the yoke connector. One cap fell off during removal and crud sat under C3. Source
  • Story: Zebra lines and no chime after a recap (Medium confidence). Another SE/30 showed horizontal lines and no chime after recapping, and swapping the analog board did not help. Replies pointed to RAM banking, since the SE/30 is picky about RAM, and the owner fixed it by correcting how the RAM was populated. Source
  • Tip: Horizontal lines cured by three analog resistors (Medium confidence). A recap write-up says horizontal lines persisted after the recap and went away after replacing analog board resistors R20 (100k 1/2W), R21 (1M 1/2W) and R25 (470k 1/2W). Removing the SMD caps by wiggling with pliers avoided ripped pads, and nail polish as a solder mask turned gummy when washed. Source
  • Tip: Full SE/30 cap set and cleaning advice (Medium confidence). The sound-issue thread names C1, C2, C7 and C11 as the rest of the set after the C3 to C6 square, and one poster advises an IPA bath with a paintbrush while avoiding vinegar as too corrosive. Others recommend generous flux and clearing holes with a syringe needle. Source
  • Story: UD8 and UE8 area prone to trace damage (Low confidence). In a thread on video faults after recapping SE and SE/30 machines, a reply says the area around UD8 and UE8 is particularly prone to trace damage and to look for corrosion on chip pins. It suggests checking about 12V at UC8 and about 5V at C11. Source
  • Tip: Garbled first-start screen: check the harness (Low confidence). A thread on an SE/30 whose screen was garbled on first power-up and clean on the second suggested checking the logic-to-analog board harness for pinched or damaged wires while recapping everything. Source

Before you start

  • Only the logic board is covered here. The analog board sits next to the tube and carries dangerous voltage: have a professional do it, or follow an experienced guide.
  • Do not open the tube, ever.

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.

  • Macintosh SE/30 recap and repair (Write-up) by dreamcast.nu. The author lists the logic board parts and talks about using tantalum capacitors.
  • Compact Mac Caps List (List) by TinkerDifferent community. A community list of capacitor values and package types for compact Macs. Check it against your board.
  • SE/30 analog board cap values (Forum) by 68kmla forum. For the analog board. Read the safety warnings first.

Logic board counts and values are from the dreamcast.nu write-up “Macintosh SE/30 recap and repair”.

Logic board

Do the surface mount ones first, working neatly in rows. The two larger axial ones are the last two jobs.

PartValueVoltsType
1 µF x 11 µF50 Vsurface mount
47 µF x 1047 µF16 Vsurface mount
220 µF x 1220 µF16 Vaxial
470 µF x 1470 µF16 Vaxial

Shopping list

13 capacitors in all, grouped by value. Buy a few spares.

Skip the sourcing

While you are in there

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Step by step

  1. Photograph both sides of the board before you touch anything. Zoom in on every capacitor. The photo is your map when you are three hours in.
  2. Unplug it, take out the batteries and let it sit. Old power supplies and CRT parts can hold a charge. If your machine has a tube, leave the tube and its board to a professional.
  3. Open it up and keep the screws sorted. A muffin tin or an egg carton works. Different screws go in different holes, and the holes never forgive you.
  4. Look for leaks. Clean any sticky residue off with isopropyl alcohol and a soft brush. A leaked capacitor leaves brown crust and can eat copper traces. Look at the traces under it, not only the part itself.
  5. Mark the polarity of every capacitor on the photo before it comes off. On an electrolytic, the stripe marks the negative leg. The board usually shows a half-shaded circle or a bar for the same spot.
  6. Remove the old capacitors one at a time. Surface mount: add fresh solder to both ends and rock the part off, or use flux and a low-melt alloy. Through-hole: heat one leg at a time and clear the hole with wick or a pump.
  7. Clean the pads and check for lifted pads or damaged traces. Clean flux off with isopropyl. A bad pad needs a jumper wire, not hope.
  8. Fit and solder the new capacitor, matching polarity. Same capacity, same or higher voltage, and it has to physically fit. Work from the smallest parts up.
  9. Clean the flux off and look at every joint. A good joint is shiny and shaped like a tiny volcano. A dull blob or a ball is a cold joint: reflow it.
  10. With a multimeter, check for shorts across the power rails before you power it on. Use the continuity or resistance setting. A reading near zero means stop and look for a solder bridge.
  11. Power it up and test everything: video, sound, controls, the lot. If something is wrong, check polarity first. It is the most common mistake and the easiest fix.

Tools

Safety

  • Good airflow, or a fume fan. Solder smoke is not for breathing.
  • Safety glasses on. Solder spits and clipped legs fly.
  • Iron in its stand when you are not holding it. Know where the cord is.
  • Touch bare metal first, or use a wrist strap. Static kills old chips.
  • No tube, no mains power supply. Leave those to a professional.
  • Wash your hands after, especially if you used leaded solder.

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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