9

I returned to my MacBook after a few days of not using it, and there was a message that the system had run out of application memory (weird...). So, I followed the recommendation and Force Quit a bunch of applications. In order to just "start fresh", I decided to kill all applications and simply restart the whole machine.

Now that I've killed the applications and restarted the computer, it won't boot. It simply displays a gray circle with a white lightning bolt on it, moving around the screen, screensaver-style. If I unplug the AC power cord, a battery indicator is displayed at the bottom of the screen.

I attempted an SMC reset, but that doesn't help. What's going on, and what should I do?

enter image description here

  • 6
    That was it! My keyboard is broken (it usually continually types the letter "T", so I have to disable it and use an external keyboard). So, when I rebooted, the system interpreted the keyboard's input as "use Target Disk Mode". I simply held down the "Cmd" key so that it became "Cmd-T", which prevented TDM. I've successfully booted! – rinogo Sep 28 '15 at 14:27
  • If you add an answer in this regard, I'll accept it. Good to have this knowledge stick around in the rare case someone else has the problem! :) – rinogo Sep 28 '15 at 14:28
  • 1
    Good to hear that your Mac works! I'll add my comment as an answer, then. – RedEagle2000 Sep 28 '15 at 14:28
  • Me ttttoo. Thanks!ttttttttttttttttttttttttttttttttttttttt – Jamey May 8 '17 at 16:13
  • Seriously, me oo! apple.stackexchange.com/questions/297518/… Did you need a hardware fix in he end? – Synesso Sep 12 '17 at 1:17
10

That looks like the Thunderbolt logo. Your Mac probably thinks that is in Target Disk Mode.

  • 1
    It was TDM! See my comment on the original question for what I did to "fix" the problem. – rinogo Sep 28 '15 at 14:29
  • Wow ... have the same problem with the same letter t busted on the built in keyboard. Is it worth replacing the keyboard? – Manfred Moser Dec 4 '18 at 15:49
  • I have the same problem (non-working/repeating "t"). Apple (Genius Bar) said it would cost $475 to replace the keyboard, because they have to replace the screen at the same time. Still a lot cheaper than a new Macbook Pro, so I'm going to do this. – John Broughton Feb 27 '19 at 19:01
2

NVRAM holds the info on where/how to boot (Target Disk Mode). You need to reset the NVRAM

0

Watch on the right of your mac, on top it has the same symbol as the logo you are showing. It is probably a cable that needs to be plugged in. If you think this means trouble go to your local apple store.

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