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Repair guide

Work out why a classic Mac will not start (chimes, sad Mac, question mark)

A flashing question mark usually means no startup disk was found, while a sad Mac or unusual chimes point at hardware such as RAM or logic board. Work through the cheap checks before opening the case.

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Diagnosis · Medium · about 45 minutes. Worth doing. Reports say this fix helps on many machines.

You are in the right place if: The Mac plays an odd chime or beeps, shows a sad Mac icon, or sits at a flashing question mark.

Before you start

  • Compact Macs contain a CRT with dangerous stored voltage; do not go past the logic board.
  • Unplug before touching RAM or boards.

Board revisions and models

Chime tones and sad Mac codes differ by model.

Parts you may need

Tools

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Step by step

  1. Note exactly what you see and hear Write down the sound and the screen. A flashing question mark is a different problem from a sad Mac.
  2. Disconnect peripherals Unplug everything except keyboard and mouse.
  3. Check the startup disk If you see a flashing question mark, check the disk's connections and try a startup floppy or CD.
  4. Check the PRAM battery Dead PRAM battery can cause odd behaviour; see the battery guide.
  5. Reseat RAM Reseat memory modules and test with fewer.
  6. Zap the PRAM Reset the PRAM using the combination for your system version.
  7. Try another power source Try a known-good power cable and outlet.
  8. Look for leak damage Look at the logic board for battery leaks and recap needs.
  9. Look up the sad Mac code Compare the codes on screen with a published chart.

Tips, tales and maybes

Found in write-ups and forum threads. These are other people's reports, not tested by us.

  • Tip (Medium confidence). A TinkerDifferent thread on testing a Macintosh IIsi logic board discusses the split between power supply and logic board faults. Source
  • Maybe (Low confidence). A flashing question mark means no usable startup disk; chimes and sad Mac codes are hardware clues. General technique, no source.

Guides we used

We wrote the steps in our own words from these. They have the photos and the full detail, so please read them and support their authors.

Boards and models vary, so check what is in front of you. A repair can involve hot tools, chemicals and, on some machines, dangerous voltages. You do it at your own risk.

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