iMac won't boot

Question

Level 1

4 points

iMac won't boot

I have a 27" Retina iMac Late 2015 with a 4gHz Intel CPU and 24 GB RAM running Mojave with Boot Camp. Last time I used it, I got errors concerning iCloud, Keychain and insufficient HD space although there have been some GB free. I decided to reboot and reset the NVRAM but when I shut down the computer, there was a white spinner that didn't disappear for minutes so I turned it off. Since then, no reboot has been possible. I have a black screen that doesn't even flicker or anything. I can hear the cooler running but no startup chime. No keyboard inputs work, not even the Caps Lock LED. I've also tried SMC reset several times but it doesn't change anything. I've already had the same problem once after upgrading to Mojave, back then it suddenly started working again, I don't know why. Any ideas?

iMac 27", 10.14

Posted on Feb 12, 2019 12:35 PM

Reply

Answer 1

Feb 12, 2019 12:40 PM in response to Slashdot81

<<...although there have been some GB free.>>

You do not say how large your HD or how much is "some GB free."

see if you can Boot into Recovery (Command R) and from the dropdown menu: Utilities> Disk Utility> run the First Aid on your Macintosh HD. If errors are found and repaired, run again until no errors reported. 

Recovery http://support.apple.com/kb/HT4718

Reply

Answer 2

Feb 12, 2019 1:48 PM in response to Slashdot81

It's a 500 GB SSD with about 350 GB in the Mac partition and abou 10GB was free when I looked at it the last time.

I'm sorry, I CAN NOT BOOT. That's the problem.

10GB free hardly seems like enough free space, that is ~3 % to successfully boot up the Mac. Typically you hear numbers of 10-15% free is minimum. Maybe it will boot with 8% (?)

You do not clearly state how far into the boot you can get, except for " I CAN NOT BOOT. "

Maybe you have other issues(?)

You can try a a SafeBoot https://support.apple.com/en-us/HT201262 and try clearing/moving storage off the Disk.

You can try Single User mode and the command line for the same purpose.

Start up your Mac in single-user mode or verbose mode - Apple Support

Reply

Answer 3

Feb 12, 2019 2:43 PM in response to Slashdot81

Up and running you can check the Console.app for log files for reported issues

or from the Finder>Go>Go To Folder> copy and paste:

/Library/Logs/DiagnosticReports

A panic report should have "panic" in the file name.

If your Mac spontaneously restarts or displays a message that it restarted or shut down because of a problem

https://support.apple.com/en-us/HT200553

Reply

Answer 4

Slashdot81 Author

Level 1

4 points

Feb 12, 2019 2:16 PM in response to leroydouglas

I already said that I have a black screen with no startup chime and no keyboard inputs accepted, so that's what I meant when I said that I can not boot. Any alternative startup modes like safe mode etc require keyboard inputs that do not work.

Reply