Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Level 1

10 points

iMac upgrade from Mojave No longer boots.

Performed the Catalina upgrade. Once it started I left it running and when I returned hours later my Apple 27" iMac with Retina 5K Display (Late 2014) would not boot.

Contacted Apple support on phone and went through several test and they indicated it was a hardware issue. Appears the iMac would not complete post.

At the Apple store they went through several test and concluded it was probably the "Logic" board as it appears the USB ports were inoperative.

Just wondering if anyone else has run into this condition and what they did about it?

Posted on Oct 13, 2019 1:56 AM

Similar questions

No entry sign on start up I’ve been running Catalina on a late 2012 iMac for some time. During the last update I was informed that the update could not be completed because of a kernel cache issue. On restarting the Mac I was presented with the no entry sign suggesting that the OS was not compatible. I opened in the Mac in Recovery mode, repaired the disk and tried again to reload the OS (automatically it tried to download Catalina). Again installation failed due to a kernel cache issue. I opened again in Recovery mode and this time erased the disk opted for a clean install. Catalina loaded ok with the latest update and all seemed well. However on trying to access some files on Lightroom I was presented with the wheel of doom and the Mac then crashed. It would not restart and I was presented again with the no entry screen. Clearly Catalina does work on this Mac configuration so does anyone have any idea as to what is going wrong?
466 9
iMac 21" Computer dead or dying? I have a 2015 iMac 21" that will not boot up. When I used disc recovery, the utility freezes at "Checking snapshot 2 of 4". I see there are other posts about this, but I cannot boot up at all on this computer. Shall I assume the disk is dead and reformat it, reinstall the software, and then use Time Machine? I am worried that not everything is backed up, but I THINK it is.... I believe it has Mojave on it. I had this experience with my 2013 27" iMac and thought it was dead, so bought the 2015. Then I erased the drive on it and now it works fine.... I use it as a second monitor. It has Catalina on it. Your help and experienced advice is greatly appreciated.
192 11
Can not boot iMac following attempted reload of Catalina OS. Not in safe or recovery mode. Only image on screen is a circle with a diagonal line through it. Can not boot iMac following reload of Catalina OS. Not in safe mode or recovery. The only image on screen is a circle with a diaginal line through it.
166 1

There are no replies.

iMac upgrade from Mojave No longer boots.

Welcome to Apple Support Community

A forum where Apple customers help each other with their products. Get started with your Apple ID.

Learn more Sign up