iMac shutting down or restarting

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Level 1

27 points

iMac shutting down or restarting

Got a 27 inch late 2012 iMac. Had a power supply problem about a year or more ago. Apple replaced it. Woke up this morning to an unconscious computer. Pushed and held power button, which brought it back to life. The night before last, the iMac must have restarted overnight, as open apps were no longer open. I have Applecare, so I'll probably be giving them a call. In the meantime, I had a look at Console. Have no idea what I'm looking at, but looked anyway. I see last night a long column of lines marked "kernel." I attached a screen shot. Is this a "kernel panic." Anyway, just thought I'd throw it out there. I'm a big Apple fan, but am disappointed in this very expensive iMac. And I'm further disappointed in the Applecare support here in Japan. Nice folks, but fairly clueless. Any thoughts out there, I'd love to hear them. Thanks in advance.

Posted on Mar 23, 2015 3:14 PM

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Answer 1

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Linc Davis

Level 10

209,547 points

Mar 23, 2015 3:22 PM in response to EddieT

Is this a "kernel panic."

No. It's a GPU restart, most likely caused by a fault in the graphics card.

Make a "Genius" a ppointment at an Apple Store, or go to another authorized service provider. You may have to leave the machine there for several days.

Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.

*An SSD doesn't need to be zeroed.

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Answer 2

EddieT Author

Level 1

27 points

Mar 23, 2015 3:26 PM in response to Linc Davis

Thanks, Linc. I'll call Apple. They'll have to come and pick up the machine to bring it to Tokyo. Last time they did this, they changed the initial user login password without telling me, and also somehow managed to completely mess up my keychain. Took an hour on the phone to someone in Australia just to get the thing working again. Anyway, thanks for your reply.

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