Q: iMac stuck in El Capitan installation loop, cannot boot...
Hi all,
We have just purchased a refurbished iMac on auction to replace a much older one which had stopped working. It's a Mid 2010 iMac 21.5inch, i3, 500GB and upgraded to 16GB RAM. The model number is A1311 / MC508LL/A. However I'm having problems immediately.
It switched on fine like a new computer, entered our details etc, got to the desktop screen, began to install software updates, Skype and customise the wallpaper, but within half hour to an hour of it being on, it suddenly rebooted itself, when it came back on I had a kernel panic screen, then it displayed the Apple logo with loading bar, but with a lot of white text on black overlayed on top.
I restarted but it refused to boot. It would not boot into safe mode either. I managed to boot to Recovery mode and attempted to reinstall the OS, allowing it to download the latest version of El Capitan (which it had on there anyway), but the installation would either get stuck at about 28 minutes remaining with the grey loading bar screen, or get to about 10 minutes remaining on the blue loading bar screen, and just reboot itself. Most of the time I see the kernel panic screen which disappears by itself and reboots.
I then created a bootable El Capitan USB using a working Mac, booted the iMac using this, erased the hard drive and then installed the OS from fresh using the USB installer. However I'm having exactly the same installation loop/reboot issue. I've tried this twice with no luck.
Between all this I've tried resetting SMC and PRAM several times. I've also run Disk Utility which doesn't find any errors using First Aid.
I'm going to assume there's a hardware issue here but I cannot identify it. Looks like it needs to be returned as faulty, but would appreciate any advice on anything else I can try to get it working please?
Thank you!
iMac, Mac OS X (10.6.8)
Posted on Jun 22, 2016 3:06 AM