Messed up partitions, can't use recovery/safe/network/etc. mode - options for reimaging?

[dogpear]

Hi,

I recently tried to (manually, not using bootcamp) set up dual boot on a MBP by doing the whole process of re-partitioning, etc. After the original OSX partition was resized, everything still worked fine.

During the installation of the second partition (a Linux one), nothing on the OSX partition was touched - only the new, empty partition left over from shrinking the OSX partition, but after quitting the process half way (an error of some sort occurred and the installation hung), the MBP no longer boots/only boots to a black screen.

This is despite trying every single different boot option available from here, none of which got me past the black screen. Note that the startup chime still happened though, just nothing after (you can still see the screen's backlight come on). However, the keyboard backlight doesn't come on, and the Caps Lock key does not work either (green light doesn't toggle), so it doesn't appear to be a case of only the display not showing anything.

I'm thinking of trying to image the disk from scratch from a working MBP, but would like to avoid taking them apart if possible - what are my options here?

Cheers.

 

[honestone]

Need to know some things:

1. What exact Mac models do you have, ie, the problematic one, and the working MBP?

2. What exact OS were you using on the problematic Mac, and what OS are you using on the working MBP?

3. Did you make any backups to an external device of the problematic Mac?

4. Is there anything you need from the problematic Mac? If the answer is no, and if both of the Macs have the needed ports, then there is a way to get the problematic Mac back in working order.

5. Do you have any robust disk cleanup/maintenance/repair program like TechTool Pro or Disk Warrior? Either of those could be used to check the health of the internal drive on the problematic Mac.

 

[dogpear]

Hi honestone,

Sorry for the (super) late reply.

1. The problematic one is the A1502, and I'm not sure about working ones - will have to come back and edit the post when I find out in the next couple days

2. It was the latest version of Sierra, and the same for the working ones

3. No backups unfortunately - at the same time (though may not be relevant), I'm also not looking to try and back up or recover data to restore its functionality, as anything important is in the cloud/etc.

4. No

5. Also no - but if required I can probably get a copy of them through work.

Thanks.

 

[honestone]

OK, there are a couple of things you can do to get ready:

1. On the good Mac, make sure you have a copy of the file "Install macOS Sierra". If necessary, you can download/re-download the latest version of Sierra, OS 10.12.4, from the App Store.

2. Your problematic Mac has two Thunderbolt 2 ports on it. The hope if that the good Mac has either a Firewire 800 port, or a Thunderbolt port on it. If that is the case, you'll need to purchase the appropriate cable so that you can boot your problematic Mac in Target Disk Mode.

Once you identify the "good" Mac, I (or someone else) can provide more assistance. One assumption I am making is that there is nothing you need from your problematic Mac.

Finally, even after you get your Mac working, you need to do 1) make a backup frequently, and 2) perform "periodic disk cleanup/maintenance/repairs, from a software perspective. Two products that are excellent for that are 1) the excellent freeware program Onyx for a lot of dick cleaning tasks, and 2) the excellent commercial program TechTool Pro. I use both of them on a weekly basis to keep both of my Macs "lean, mean, and clean" (I also do daily disk cleanup). Finally, although Time Machine (comes with the Mac OS) can do backups, I prefer SuperDuper!, as it makes a bootable clone. It makes recovery easier, and in fact, saved "my bacon" a few times.

 

[dogpear]

Thanks honestone! I'll give using Target Disk Mode a go once I can borrow a working Mac, and post back here how that goes.

My cause of concern is that I vaguely recall being told that (tried going into an Apple Store to have the issue fixed - all they offered was to replace the motherboard for $700 or something along those lines) target disk mode should still bring up a menu on the problematic machine which currently isn't possible as every possible boot option has a black screen. I'll give it a go though.

 

[honestone]

The thought is that via Target Disk Mode, the hard drive in your problematic Mac will appear on the desktop of the good Mac. You can then use whatever utilities you have on the good Mac to try and fix things on the "bad" Mac. I suspect you only have Disk Utility on the good Mac, which (hopefully) would be good enough.

 

[dogpear]

After getting my hands on a thunderbolt-thunderbolt cable, it seems like things may be a little worse off than I thought (both are model A1502). I tried the following steps:

1. Connect the two laptops via the thunderbolt-thunderbolt cable
2. The working MBP was logged into an admin account, with Sierra ready to install
3. The faulty MBP was booted while holding the 'T' key, greeting me with a black screen and the booting chime noise (same behaviour as every single other possible shortcut-based boot option)

The faulty MBP that should be in target disk mode at this point did not appear on the desktop of the working MBP, and a second disk also wasn't shown as an install target option in the Sierra installer.

I'm a little lost as to what I could do now - do you have any suggestions? Thank you in advance!

 

[honestone]

First, there are 9 different 13" MacBook Pro models A1502:

http://www.everymac.com/ultimate-mac-lookup/?search_keywords=A1502

So, it would help if you can identify the exact one you have that is causing issues.

From your description, there is a very good change that the internal SSD has gone bad. The SSDs in each of those models are PCIe-based flash storage, which means the SSD looks like a card. They can be replaced, but such SSDs are not cheap. Also, until you obtain the exact model you have, I can't point you to an exact repair guide.