I’ve tried everything I’ve read about trying to reinstall High Sierra. I erased my disk and am trying to install macOS High Sierra. When I select the disk I want to install to, it is grayed out and says it’s locked. I have absolutely no option to unlock the disk. Am I missing something? I am going to be selling this computer as it is an older mode but wanted to reinstall the OS for the next user.
iMac Line (2012 and Later)
Luckily it'll take a nice 3.5" Hard Drive, but will need a thermal addition...
https://eshop.macsales.com/shop/hard-drives/3.5-SerialATA
https://eshop.macsales.com/upgrades/imac-21-5-inch-mid-2011-2.5-ghz
https://eshop.macsales.com/item/OWC/DIYIMACHDD11/
https://player.vimeo.com/video/139361984?autoplay=1&title=0&byline=0&portrait=0
Or an external drive or SSD.
So, I’ve done the installs and it worked great. However, now it will only work when my other iMac is powered on and the fan blows VERY strong and loud. Is this normal?
the fact that my older model only works when my new iMac is powered on is very puzzling.
It worked perfectly for about 2-3 weeks. Then last Wednesday I could t get my older iMac to turn on. I turned on my newer iMac and then tried to turn on my older iMac and it came on. Then I shut down my new iMac and the older one just shut down. They’re not wired together in any way. It’s odd.
the loud fan started just yesterday.
that is correct, the base system as that is the only option that I am given. Btw, thank you!
Which exact iMac is it?
What exact Disk are you trying to install to... sounds like you maybe chose OSX Base System/
Your drive may be dead or dying.
Do you have an external Drive you can Install to?
In Disk Utility's View Menu, choose Show all Devices, what is the top one or two?
I’m not sure why it says solved.
It shows ST............AS media and OS X Base System
Sounds like drive has died, do you have an external drive you can install to?
Ok, thanks to that info, I was able to get it running via an external hard drive which tells me my other internal drive is dead which makes sense. How do I find one that will work with my computer?
It’s the exact same model. I’m looking on Amazon now for the replacement. I sincerely appreciate your help!
No, not normal... sounds like a wiring problem if I understand what you're saying.
I think it's your house wiring, try a different receptacle.
Reinstalling macOS High Sierra - unable to unlock disk
