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MBA 2015 - Problem Getting to Clean Install

txa1265

txa1265

macrumors 65816
Original poster
Aug 15, 2002
1,123
468
Corning, NY
I have a 2015 11.6" MacBook Air and would like to do a clean install of Mac OS X Mojave ... but I simply can't seem to get there.

Some things:
- When I boot up, even after power-down, the login screen appears *really* fast - like less than 5 seconds.
- The Command-R doesn't respond - it just goes from startup sound to login.
- In fact NONE of the startup keys seem to do anything.
- I downloaded the OS image from Apple, and followed all the instructions to create a bootable USB drive (it is a 64GB stick), but it won't show me the boot manager.
- I also can't get it to recognize the USB drive as a possible boot volume in Startup Disk - yet on my MacBook Pro it sees it just fine.

I honestly don't know what to try next - if the nearest Apple store wasn't ~2 hours drive away I would do that, but alas ...
 
txa1265 said:
I have a 2015 11.6" MacBook Air and would like to do a clean install of Mac OS X Mojave ... but I simply can't seem to get there.

Some things:
- When I boot up, even after power-down, the login screen appears *really* fast - like less than 5 seconds.
- The Ctrl-R doesn't respond - it just goes from startup sound to login.
- In fact NONE of the startup keys seem to do anything.
- I downloaded the OS image from Apple, and followed all the instructions to create a bootable USB drive (it is a 64GB stick), but it won't show me the boot manager.
- I also can't get it to recognize the USB drive as a possible boot volume in Startup Disk - yet on my MacBook Pro it sees it just fine.

I honestly don't know what to try next - if the nearest Apple store wasn't ~2 hours drive away I would do that, but alas ...
Click to expand...
Command-R, not control-R, is the recovery command.
 
Audit13 said:
How about using Internet recovery to reinstall the original os, download Mojave again, create the installer, and boot from the usb drive.
Click to expand...

Do you have an alternate method of getting to internet recovery? Because as I have very clearly stated a couple of times now - CMD-R (and therefore CMD-Option-R) DOES NOT WORK. My Air boots very, very fast right to the login prompt, and for whatever reason doen’t respond to startup keys.
 
You didn't mention command+option+r in any of your posts. Even though command+r doesn't work does not automatically mean that command+option+r won't work.

Command+r won't work if the drive does not have a recovery partition.

Good luck.
 
Audit13 said:
You didn't mention command+option+r in any of your posts. Even though command+r doesn't work does not automatically mean that command+option+r won't work.

Command+r won't work if the drive does not have a recovery partition.

Good luck.
Click to expand...

Thanks - and apologies for being snippy ... been frustrating, there is definitely life left in this MBA but it needs to be wiped and started fresh and I have done this in the past and never had an issue.

I am pretty certain I have tried all the key combinations ... but I appreciate you making the distinction and I will try to go through everything again just to be sure. Also contemplating adding BootCamp to see if that can help me force the StartUp Disk manager to appear (maybe the USB Flash will appear under windows).

Weird stuff.
 
Also, if you insert your USB installer flash drive - then open System Preferences/Startup Disk, change the boot drive to that flash drive. It should appear as a choice. You will need to unlock that Startup Disk pane by clicking the lock in the bottom left corner of that pane. After selecting your installer drive, then choose Restart from the Apple menu.
 
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Audit13 said:
Have you tried a usb keyboard?
Click to expand...

I did a while back, but not sure I explored it thoroughly - will drag one home with me this weekend :). Thanks for the reminder.

DeltaMac said:
Also, if you insert your USB installer flash drive - then open System Preferences/Startup Disk, change the boot drive to that flash drive. It should appear as a choice. You will need to unlock that Startup Disk pane by clicking the lock in the bottom left corner of that pane. After selecting your installer drive, then choose Restart from the Apple menu.
Click to expand...

Unfortunately on the MBA the USB card doesn’t show up as a boot drive option - but it does on my MacBook Pro.

I think I might copy the file onto the MBA, then use the terminal to do the ‘format as boot disk with installer’ option from there just to confirm that there isn’t something else going on.
 
What model of MBPro do you have? Is it 2017 or newer?
Did you use THAT newer MBPro to make the bootable flash drive?

Have you tried an NVRAM reset? (restart, holding Option+Command+p+r) You should get the boot chime. Keep holding the same 4 keys until you hear the boot chime 2 more times, then release all keys to allow a normal boot.

If it continues to ignore the bootable flash drive, let it boot up to whatever system is already installed on your MBAir, then plug in the bootable USB, and open your System Information (that's in your Applications/Utilities folder). Go to the USB tab, and look for your USB device. (It should also be listed under the Storage tab)
 
DeltaMac said:
What model of MBPro do you have? Is it 2017 or newer?
Did you use THAT newer MBPro to make the bootable flash drive?

Have you tried an NVRAM reset? (restart, holding Option+Command+p+r) You should get the boot chime. Keep holding the same 4 keys until you hear the boot chime 2 more times, then release all keys to allow a normal boot.

If it continues to ignore the bootable flash drive, let it boot up to whatever system is already installed on your MBAir, then plug in the bootable USB, and open your System Information (that's in your Applications/Utilities folder). Go to the USB tab, and look for your USB device. (It should also be listed under the Storage tab)
Click to expand...

Yes - I used the recently updated 2018 15” MBPro to create the boot disk ...

I did also try the NVRAM reset, and again it just came right to the login and ignored keys.

I will take a look at the SysInfo as well.

Thanks for the suggestions!
 
Be sure to try an external USB keyboard.
From your symptoms, I suspect that you have a dead key, or two, on your MBAir.
That would explain why it is ignoring the various boot key-combos
 
Thanks again ... over the holidays I played with a few things:
- tried all of the various ‘do something at startup’ key combinations I could find. Nothing caused anything at all to happen.
- Used an external Bluetooth keyboard - nothing happened, but I am concerned that since it is a PC keyboard I might need a Mac-specific one.
- Reformatted the USB drive using the MBAir as bootable - it even says so in the Disk Utility info - an made it an installer for Mojave ... yet it won’t show up as a boot option in Startup Disk.

I have not done BootCamp yet to see if that would help, nor have I bought a Mac-specific USB keyboard. I suppose those are next before I contemplate using it as a flyswatter ...
 
Were you able tot try a USB keyboard too?

It shouldn't matter whether the Keyboard, Bluetooth or USB, is Mac or PC specific. I've used both types with my MBP and PC desktop.
 
You might try installing Mojave from the App Store and see if that allows you to then boot into recovery for a clean re-install.
 
Probably a stupid question - but have you tried the other cmd-button? If it's the left one you normally used, try the right for cmd-r?

(just in case the left one is faulty)
 
JonLa said:
Probably a stupid question - but have you tried the other cmd-button? If it's the left one you normally used, try the right for cmd-r?

(just in case the left one is faulty)
Click to expand...

Yes - I actually have tried that as well. Sadly that doesn’t change things.
 
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