My Early 2006 MacBook Pro (Core Duo, NOT Core 2 Duo, Model Identifier MacBookPro1,1) has four partitions: EFI, Snow Leopard HFS+, Ubuntu 11.04 ext4 and Windows XP SP3 NTFS.
I don\'t know what happened, but starting yesterday morning neither XP nor Ubuntu would boot. I would select either one in the rEFIt boot menu, then I\'d just get a black screen with a rapidly flickering cursor.
Because neither XP nor Ubuntu would boot, I figured there was a problem with the MBR. rEFIt\'s partition tool said that the MBR was still in sync with the GPT. I booted from the Parted Magic rescue CD and rewrote the MBR:
# fdisk /dev/sda
The above prints the existing partition table so I can inspect it, then writes it back again. But this has the side effect that a fresh boot loader is written.
After this I could boot XP just fine, but Ubuntu still would not boot, with the same symptoms.
I then used Parted Magic to mount Ubuntu\'s partition and run Ubuntu\'s update-grub:
# mount /dev/sda3/mnt
# mount --bind /dev /mnt/dev
# mount --bind /proc /mnt/proc
# mount --bind /sys /mnt/sys
# chroot /mnt
At this point while we are still booted from Parted Magic we are running from the Ubuntu filesystem
Update-grub finds all three of my OSes and claims that it completed successfully, but still it cannot boot.
I am running rEFIt 0.14, which had been working quite well for quite some time, as had both Ubuntu and XP.
Thanks for any help you can give me,