When good Macs go bad: Steps to take when your Mac won't start up
Posted 06 May 2013 - 05:27 AM
Not sure what it does exactly"
There is absolutely no need to type that before reboot. If you are at the point of rebooting, you needn't do anything but reboot. The command mounts the startup volume. You need that command to see files on the volume or to apply any changes to it, such as the FSCK command to repair the volume.
Posted 06 May 2013 - 05:30 AM
Either you didn't hold the keys long enough (as much as 40 seconds for some models) or the system is pre-OS 10.7. For any older system, you boot to the DVD, not the recovery partition.
Posted 06 May 2013 - 05:39 AM
Total waste of time. The only reason to verify is if you are booted to that volume (when you cannot repair it). If you are booted to the recovery partition, as described in this article, just repair disk, never verify.
Posted 06 May 2013 - 05:50 AM
You absolutely did. Erasing a drive that tests error-free (after repair) in Disk Utility is a waste of time and causes unneeded terror in case the backups are not complete. Just say "No" to any "genius" who says you need to erase after DU shows no errors.
"First, we managed to get Julian’s Mac usable enough to back up crucial data. That was probably the most important step we took."
You could have backup up data without erasing the drive. Terminal can do that quite well, thank you.
"Second, all those steps ruled out numerous other issues; it was because of the freshly-wiped hard drive that the new Genius was able to conclude a logic board failure was to blame for JV’s Mac’s problems."
They could have tested with Apple Hardware Test mode and found that bad logic board. They could have booted to an external drive and gotten the hang or kernel panic. That would have confirmed a non-drive hardware issue.
I'm curious to know if the RAM was replaced at the same stage as the logic board. If so, it was probably bad RAM, and the logic board was fine.