Recap guide

Recap the Macintosh IIci and IIsi

The IIsi is notorious for leaky caps, and both the IIsi and IIci have power supplies that need recapping.

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.

• IIci supply, Astec (Low confidence). How to tell: Maker named on the supply; a console5 note warns not to trust the 614 or 699 Apple numbers and to check the real maker. Capacitors: No values in the thread. Capacitor list differs from other revisions: not known. Source
• IIci supply, GE 9T89Y5005G11 (Apple 699-0392) (Medium confidence). How to tell: GE model number on the supply. Capacitors: A recap kit exists for it; no values in the thread. Capacitor list differs from other revisions: not known. Source
• IIsi supply (Sony) (Medium confidence). How to tell: Sony supply of about 1991 in one article. Capacitors: 12 electrolytics: 2 SMD on a daughterboard and 10 through-hole, including a 400V cap in the AC section. 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.

• IIsi power supply (Medium confidence). One write-up counts 12 caps in the IIsi PSU, including two SMD on a daughterboard and a 400V part. The author recapped only 3 of the 12 and defers to a repair service's list for values. Source
• Leaky IIsi board (Low confidence). A logic board testing thread confirms the IIsi's leaky-cap reputation and the split between PSU and board problems. Source
• IIci supply (Low confidence). A request thread for the IIci supply points to a wiki list and a Console5 kit for Astec or GE supplies. 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: Five IIcis, five leak patterns (Medium confidence). A refurbisher reported five IIcis that all showed electrolytic leakage, with lifted pads at C2 and C3 near the sound chips, corroded 74HC132-family logic chips, battery damage on one and contamination on another. He replaced leaked logic chips and advises replacing the 74ALS240 below C16 if NuBus slots fail. Source
• Story: Shutdown after hours traced to leak damage (Low confidence). A IIci recapped with tantalums still shut down after hours, and the cause was broken traces around UE13 and UD13 plus a failed 74HC132 at UE13, found by continuity testing. Leaked electrolyte had hidden damage beyond what was visible. Source
• Tip: Alcohol bath after caps are off (Low confidence). One restorer received a IIci with the surface-mount caps already removed but corrosion remaining and a badly leaking PSU. He replaced every cap, cleaned the board in an isopropyl alcohol bath and serviced the floppy drive. 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.

Manuals and technical documents

Service manuals, schematics and datasheets for this machine, kept in our own library. Check your own board and part numbers against them.

• Apple Macintosh Service Guide - Macintosh IIcx and IIci (Service manual)

All 1 documents for Macintosh IIci and IIsi in the library

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.

• Capacitor List for IIci Power Supply (Forum) by TinkerDifferent forum. Request thread; answers point to a wiki list and a Console5 kit for Astec or GE supplies
• Capacitor replacement in a Macintosh IIsi (Big Mess o' Wires) (Write-up) by Big Mess o' Wires. Partial recap (3 of 12 PSU caps), explains symptoms; values are deferred to a repair service's list
• How To Test Macintosh IIsi Logic Board (Forum) by TinkerDifferent forum. Confirms IIsi leaky-cap reputation and the PSU-vs-board split

IIci Delta power supply (14 parts)

From oldcrap.org's list for a IIci with the Delta supply, noted from the original parts. Two of the 1000 uF 16 V parts have no ref on the list.

IIci logic board (14 parts)

From oldcrap.org's list. Most are surface-mount (SMD) parts, which are the ones that leak onto the board.

Shopping list

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

• 8 x 47 µF, 16 V (check your board): Amazon · eBay
• 4 x 470 µF, 16 V (check your board): Amazon · eBay
• 3 x 10 µF, 50 V (check your board): Amazon · eBay
• 3 x 1000 µF, 16 V (check your board): Amazon · eBay
• 2 x 10 µF, 16 V (check your board): Amazon · eBay
• 2 x 470 µF, 200 V (check your board): Amazon · eBay
• 1 x 2.2 µF, 50 V (check your board): Amazon · eBay
• 1 x 220 µF, 16 V (check your board): Amazon · eBay
• 1 x 470 µF, 25 V (check your board): Amazon · eBay
• 1 x 470 µF, 35 V (check your board): Amazon · eBay
• 1 x 1000 µF, 35 V (check your board): Amazon · eBay
• 1 x 2200 µF, 10 V (check your board): Amazon · eBay

Skip the sourcing

• Ready-made kit: Amazon · eBay
• Already recapped: Amazon · eBay

While you are in there

• Need the machine itself?: Amazon · eBay
• A box of spare capacitors: Amazon · eBay

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

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

• Temperature-controlled soldering station. Steady heat so you do not cook pads. Most recaps are done between 320 and 350 C. Top: Hakko FX-951 · Mid: Hakko FX-888D · Budget: Pinecil
• Good solder. Rosin-core 63/37 flows and looks right. It is cheap and it matters. Kester 44 63/37
• Flux. Flux is what makes old joints let go and new joints flow. MG Chemicals flux pen · Chip Quik flux syringe
• Low-melt alloy (for surface mount). Melts old solder on both ends of a surface mount part at once, so it lifts off cleanly. Chip Quik SMD1
• Desoldering tool. Clears the old solder out of through-hole pads. Top: Hakko FR-301 · Mid: Engineer SS-02 pump · Budget: Solder wick
• Fine tweezers. For holding small surface mount parts exactly where you want them. ESD-safe tweezers
• Board holder. A third hand for the board, so both of yours are free. PanaVise circuit board holder
• Magnification. You cannot fix what you cannot see. Surface mount parts are tiny. Top: Stereo microscope · Mid: Head visor · Budget: Lighted magnifier
• Multimeter. Continuity, shorts and rail voltages. The one test that saves boards. Top: Fluke 117 · Mid: Fluke 101 · Budget: AstroAI
• ESR and capacitor tester. Checks old capacitors and your new ones before they go in. Top: Peak Atlas ESR70 · Budget: LCR-T7
• Isopropyl alcohol (99%) and a brush. For cleaning leaked goo and flux. Use the high-percentage kind. MG Chemicals 99.9% isopropyl
• Brass tip cleaner. A clean tip transfers heat. A dirty one does not. Hakko 599B
• Fume extractor. Pulls the smoke away from your face. Hakko FA-400 · Budget: Small bench fan
• Precision screwdrivers. Most old gear uses a mix of Phillips, Torx and security bits. iFixit Pro Tech Toolkit
• Kapton tape. Heat-proof tape to protect parts that sit close to the one you are changing. Kapton tape

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.

More

• All recap guides
• The interactive Recap Bench
• Fix a dead vintage computer
• Macintosh IIci on the timeline
• Macintosh IIsi on the timeline