My Mac will not start up. I went to recovery mode and made a backup of everything on an external drive. Now the Mac only starts up from the external drive.

I have OS X 10.10, Yosemite. I tried to backup and restore but it failed.

Most of the time my internal hard disk is not mounted. I ran Disk Utility today and got the following message for my HD Error: Partition Map check failed because no slices were found

How can I fix my Mac and make it start without the external drive?

  • 1
    so the holding "cmd+r" during boot is not working ?
    – Ruskes
    Commented Jun 26, 2015 at 7:27
  • it does work. Thats how I transferred all my data to my external hard disk.
    – Rish
    Commented Jun 26, 2015 at 7:35
  • 1
    Did you try formatting the internal disk?
    – tubedogg
    Commented Jun 26, 2015 at 7:36
  • Is that by erasing it? I tried that but it hangs halfway.
    – Rish
    Commented Jun 26, 2015 at 7:37
  • and when I go into recovery mode, it does not connect to my wifi. However it connects to it when I boot up from my external drive.
    – Rish
    Commented Jun 26, 2015 at 7:37

1 Answer 1


Looks like a disk problem, dying. In the Recovery Partition (start while holding CMD+R), start DiskUtility do Repair Disk. Even when the issue is gone after that, prepare to have the disk replaced.

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