Flashing Question Mark
Apple Classic Macintosh
Severity: CriticalWhat Does This Error Mean?
A flashing question mark folder means the Mac cannot find a valid startup disk. The hardware is working fine — the Mac simply cannot locate a System Folder to boot from. Check that a disk with a valid System Folder is inserted or connected.
Affected Models
- Macintosh Plus
- Macintosh SE
- Macintosh Classic
- Macintosh II
- Macintosh LC
- Macintosh Quadra
- Power Macintosh
- Basilisk II emulator
Common Causes
- No startup disk connected or inserted
- Hard drive has failed or is not spinning up
- System Folder on the startup disk is damaged or missing
- SCSI chain problem — incorrect termination or ID conflict
- Floppy disk ejected or not inserted on diskless Macs (128K, 512K)
How to Fix It
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Insert a bootable floppy disk or CD-ROM.
If you have a Mac OS install disk or a Disk Tools floppy, insert it and restart. The Mac will boot from the floppy and you can investigate the hard drive.
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Check that the hard drive is powered on and connected.
External SCSI drives must be powered on before the Mac. Listen for the drive spinning up — if you hear clicking or silence, the drive may have failed.
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Check SCSI termination and device IDs.
SCSI chains must be terminated at both ends. Each device must have a unique ID (0-6, with 7 reserved for the Mac itself). Incorrect termination or duplicate IDs prevent the Mac from seeing the drive.
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Boot from a floppy and reinstall the System Folder on the hard drive.
If the hard drive appears on the desktop after booting from floppy, the System Folder is likely damaged. Run the Installer from a Mac OS install disk to reinstall system files.
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Reset PRAM (Command + Option + P + R at startup).
Corrupted PRAM can cause the Mac to forget which disk to boot from. Resetting PRAM restores the default startup disk selection.
Frequently Asked Questions
What is SCSI and why does it matter for Classic Macs?
SCSI (Small Computer System Interface) is how Classic Macs connect to hard drives, CD-ROM drives, and scanners. It uses a daisy-chain cable with specific termination and ID rules. If any device in the chain is misconfigured, the Mac may not see any drives.
Can I still get bootable floppy disks for Classic Macs?
Original Apple floppies are rare, but you can create bootable floppies using another Mac with a floppy drive and disk images from the Macintosh Garden or similar archives. For emulators, disk images can be mounted directly.