« previous next »
Pages: [1]   Go Down

Author Topic: What does this mean?  (Read 1782 times)

Offline jwboyd

  • Super Duper Poster
  • ****
  • Posts: 912
    • View Profile
    • http://
What does this mean?
« on: December 04, 2016, 04:19:19 PM »
I wanted to start up from a Carbon-Copy-cloned external drive.

It did not start up, but a circle with an arrow-pointed lightning bolt through it jerked its way diagonally across the screen.

I powered down, then powered up again. I am running on that external drive now and can detect no problems.

My guess is that this external drive may be beginning to fail.

Your thoughts?

Thanks!
Joe
« Last Edit: December 04, 2016, 04:19:47 PM by jwboyd »
Logged
I'm not a complete idiot -- a few parts are missing!

Offline jchuzi

  • TS Addict
  • *****
  • Posts: 3094
    • View Profile
What does this mean?
« Reply #1 on: December 04, 2016, 06:07:36 PM »
I would suggest running the Apple Hardware Test but I don't know if you can run it on an external drive. If that's not the case, do you have Drive Genius, TechTool Pro or TechTool ProToGo? They can do a variety of tests. If none of these are available, run SMART with Disk Utility. It's not the last word but you may find something.

EDIT: I forgot about this: If you have set CCC to clone the Recovery Partition, you can boot from the RP on the external drive and run the AHT.
« Last Edit: December 04, 2016, 06:12:16 PM by jchuzi »
Logged
Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P700, Photoshop CC, Lightroom CC, MS Office 365

Offline Xairbusdriver

  • Administrator
  • TS Addict
  • *****
  • Posts: 26388
  • 27" iMac (mid-17), Big Sur, Mac mini, Catalina
    • View Profile
    • Mid-South Weather
What does this mean?
« Reply #2 on: December 04, 2016, 06:57:39 PM »
Sounds like you got a "Target Disk" mode icon! Would you believe I can't find an image of that emblem/icon?! wallbash.gif Did you happen to have the "T" key held down when you tried the startup? dntknw.gif Maybe there's something in the CCC Help text...
Logged
THERE ARE TWO TYPES OF COUNTRIES
Those that use metric = #1 Measurement system
And the United States = The Banana system
CAUTION! Childhood vaccinations cause adults! :yes:

Offline kimmer

  • Administrator
  • TS Addict
  • *****
  • Posts: 9086
    • View Profile
What does this mean?
« Reply #3 on: December 04, 2016, 07:18:24 PM »
I'm wondering if you are using a Thunderbolt cable? Look at the image on this page for information on using Target Disk mode:

https://answers.syr.edu/display/os/Target+D...c+Data+Transfer
Logged

Offline jwboyd

  • Super Duper Poster
  • ****
  • Posts: 912
    • View Profile
    • http://
What does this mean?
« Reply #4 on: December 04, 2016, 08:12:35 PM »
Yes, Kimmer, it was the Thunderbolt icon!

No idea why, as I have no Thunderbolt cables connected. All my externals are on USB.

The mystery deepens. . .

Joe
Logged
I'm not a complete idiot -- a few parts are missing!

Offline jchuzi

  • TS Addict
  • *****
  • Posts: 3094
    • View Profile
What does this mean?
« Reply #5 on: December 05, 2016, 06:02:13 AM »
Jim is probably right about why it happened, namely that you pressed T during startup.
Logged
Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P700, Photoshop CC, Lightroom CC, MS Office 365

Offline jwboyd

  • Super Duper Poster
  • ****
  • Posts: 912
    • View Profile
    • http://
What does this mean?
« Reply #6 on: December 05, 2016, 09:15:04 AM »
Mystery solved!

I was able to replicate the condition by pressing T on startup.

Thanks to Kimmer, Jim, and Jon for enlightening me.

While I was at it, I ran TechTool Pro and DiskFirstAid on that drive and corrected a couple of things. Now all is well.

Joe
« Last Edit: December 05, 2016, 09:16:14 AM by jwboyd »
Logged
I'm not a complete idiot -- a few parts are missing!
Pages: [1]   Go Up
« previous next »