Yosemite no longer booting up

[bmac89]

Hello,

I have Yosemite Public Beta installed on an external hard drive and have been succesfully booting from it on my Imac and Macbook. Both are running Snow Leopard on the internal hard drive.

However it will no longer boot up on my Macbook and does not even recognise Yosemite when I press the "alt/Option" key at boot up. However it still works succesfully on my Imac.

When I plug the drive into the macbook and go to System Preferences > Startup Disk it does not even show Yosemite, however the drive is displayed in the finder as an external drive. Seems very strange - especially when it was previously working.

Any ideas how to get it working on the macbook again?

Thanks

 

[maflynn]

Is it possible you unplugged the drive before ejecting it?

Sounds like a reinstall is in order.

 

[bmac89]

Is it possible you unplugged the drive before ejecting it?

Sounds like a reinstall is in order.

Definitely haven't unplugged until the computer has fully shutdown and the light on the drive goes off.

It seems strange it works on Imac but no longer on Macbook.

 

[maflynn]

Definitely haven't unplugged until the computer has fully shutdown and the light on the drive goes off.

It seems strange it works on Imac but no longer on Macbook.

That is odd.

What happens when you boot up holding the option key, does the drive show up?

 

[bmac89]

That is odd.

What happens when you boot up holding the option key, does the drive show up?

Macbook = no
Imac = Yes

Previously both worked.
Both computers recognise the drive as an external hard drive once booted into Snow Leopard (in the finder), however the macbook does not recognise it in Preferences > Startup Disk.

All I can think is that possibly turning the computer off means the external hard drive loses power and does not properly "shutdown". However I am not sure whether this is even an issue and I can't see any way around this other than using a mains powered drive or an internal partition. However I would assume many others are using the same method as me to boot Yosemite from an external hard drive. Still very puzzling to me!

 

[bmac89]

I hope someone can help me out.

To add to the strangeness of this....

While pressing alt/options shows no alternative boot options on my macbook...

when I go to Preferences > Startup Disk on the macbook in addition to the internal drive it does show the Mavericks disk but NOT Yosemite!

Mavericks and Yosemite are both installed on the same exteral hard drive, but separate partitions. Previously they both successfully booted from my macbook using alt/option and they both continue to successfully boot from my Imac.

So now the only way I can boot Yosemite from my Laptop is to:

1. Boot Snow Leopard from Internal drive as normal.
2. Go to Preferences > Startup disk, select Mavericks and press restart.
3. Once in Mavericks go to Pref > Startup Disk, select Yosemite and press restart.

So basically I need to boot the computer 3 times before I can use Yosemite. Not to mention it takes a long time to boot Yosemite.

Any ideas or help appreciated.
Thanks

 

[blazhennyi]

NO Startup up (neither Windows or Yosemite) appearing after crash.

Hi There,

I successfully installed Yosemite and have been enjoying a smooth ride for three days until..... It just froze and when i go to reboot, I cannot see any start up disk including windows.

I do not think this is hard drive failure: The gray screen goes to the folder with a question mark on it.

I've tried option on start up and NOTHING...

Any advice?

 

[53kyle]

Hi There,

I successfully installed Yosemite and have been enjoying a smooth ride for three days until..... It just froze and when i go to reboot, I cannot see any start up disk including windows.

I do not think this is hard drive failure: The gray screen goes to the folder with a question mark on it.

I've tried option on start up and NOTHING...

Any advice?

It's a hard drive failure.

Every symptom points to it. Freezing, and then nothing including windows will work. Software issues won't affect other partitions of a hard drive. Find a way to backup your data (such as target disk mode) and replace the hard drive.

 

[bmac89]

Anyone able to help me with my original issue with booting Yosemite.
It seems so strange that it works on Imac but not Macbook, unless you boot 3 times as described in my previous post.

 

[bmac89]

Strangely it has started booting up again after 1 week of not working. Absolutely no reason why it stopped working and no reason why it would start working again.