URGENT HELP NEEDED: mid-2012 rMBP Won't Boot

Hello, forum

I was using my father's mid-2012 base model 15" rMBP to set up his iPhone. iTunes required a software update so I went ahead and updated everything, i.e. iTunes, iLife software, OS X 10.8.5, etc. (the rMBP was still on Mountain Lion). After rebooting to install the OS X bundle update and finishing the update process, I got an error saying that there was an unforseen error in updating and nothing was installed. After that, I had to hold the power button to switch the laptop off. Now, whenever I boot, I get the error attached in the screenshot on the Apple logo screen.

Please help. I'm at my wits end and want to avoid an OS reinstall at all costs.

Thanks in advance.

Raptor

Nik said:

Can you boot into Recovery Mode when holding down Cmd+R on startup?

Click to expand...

Hi,

I've identified the issue as this. It seems that the issue was because of a faulty thunderbolt update. The updates had been pending for a long time.

Yeah, I can boot into Internet Recovery Mode. I can even use the local recovery partition. No hardware issue. Just an issue in the OS X installation.

Any help?

Raptor

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Hi,

So I read through the many Apple Support Forum threads on this issue and have decided to reinstall the OS. However, I want to backup the important files before doing so. Is there any way to do that without booting? Can I use a Linux live USB disk (such as GParted)? I'm aware that data is retained with a reinstall but I really can't take a chance here.

Raptor

swordfish5736 said:

if you've got another mac with a thunderbolt port then you can use target disk mode.

Click to expand...

I do have that but I don't have a thunderbolt cable. In fact, that was my first thought.

Raptor

swordfish5736 said:

Apple sells the 0.5m cable for $29.00
If you want to get a backup of all the files before reinstalling OS X it may be the easiest way.

Click to expand...

Unfortunately I'm not in the US and don't have enough time to purchase one online.

I figured out a way. I realised that I can use terminal in the local recovery mode. I can then use the cp command with the R flag to copy the user directory onto an external HDD. I ran into the hurdle of Mac not writing on NTFS, so I am in the progress of backing up an old HDD and reformatting it to FAT32.

Raptor

EDIT: Just remembered that I need to use HFS+ instead of FAT32 because many of the files are larger than 4GB.

Hi, all

So I managed to backup all the data. Now I'm reinstalling drivers. A quick question: can I use a Mavericks USB drive to install 10.9 over the existing but corrupt 10.8 installation?

Raptor

Okay, so out of the frying pan and into the fire. I reinstalled Mountain Lion. Now, I'm getting a kernel panic on boot. So I'm stuck in a "Your computer was restarted because of a problem" loop. Any help?

Raptor

UPDATE: I did a PRAM reset. Now I'm stuck in a boot loop without the kernel panic screen.

simon48 said:

What happens if you try booting into verbose mode (command + V)?

Click to expand...

Woops. Forgot to check single user and verbose modes. Out of options, I went ahead with another OS reinstall. I'll check that if the problem persists after this.

Raptor

Okay, still there. Single user mode is working.

What can I do to fix this kernel panic bootloop?

UPDATE: Verbose mode crashes again.