Mac Won't Start Up: Flashing Folder with Question Mark

There is a condition that may occur on some Macintoshes where the system will not start up after the power has been turned on. The machine will give its normal system chime indicating that the system has passed some preliminary tests, but then the screen will show a folder with a question mark in it and the computer will not start up. There can be several reasons for why this may be happening.

The directory database, which keeps track of where files are stored on the hard drive, may have become corrupted. The corruption can often be repaired by utilities such as Disk First Aid for Mac OS 7-9 and Disk Utilityfor Mac OS X, which can be found on most system software install CDs. To initiate a repair, insert the system software CD into the CD drive of the affected computer and turn the system off. When the machine has shut down, turn it on again and hold down the 'C' key on the keyboard. The computer will automatically boot up from the CD, allowing you run the disk repair utility from the Utilities folder on the CD. On a Mac OS X system software installation disk, you will need to select Disk Utility from the Installer menu. Occasionally, it may be necessary to use a third-party disk repair utility such as TechTool Pro from MicroMat or Diskwarrior from Alsoft.

Another problem that can occur is the driver on the disk itself can become corrupted. If this is the case, the hard disk (HD) will not appear in any disk repair utility. This is a problem because you will need to reinitialize the HD, which will cause all the data on the HD to be lost. If the computer has a built-in Firewire port, it may be possible to boot it in Firewire Target Disk Mode on another Firewire-equipped Macintosh and copy the important files before reformatting the disabled HD.

The last sort of problem is the most severe: The hard drive's mechanical parts may have failed, which means the data on the drive is completely inaccessible. There are companies that will (for several hundred dollars) attempt to recover the data of such drives, but for most people the cost is prohibitively expensive. The best solution in this case is to have and maintain a current backup of important files.