Problem with Mac Hard Drive..

[chenaletheia]

Hi,
I'm selling my old 2015 27" iMac. I reformatted my Hard drive using the directions on apple's website, but ended up seeing the flashing folder screen on startup. I open up recovery mode and try to reinstall OS. No bueno. I try to use Time Machine to restore the Mac - no bueno. I try to use Disk Utility to repair/erase the hard drive. Still no bueno.

Now I'm trying to figure out what to do. I've found some videos describing how you can use the Terminal to delete external hard drives - but I'm on sure if I can do that with my internal hard drive? (I've attached a photo of what I see when I run diskutil list)

Bottom line is, I can't start up the Mac and I don't know how to fix it. None of the recovery options work.

Can any of you help me with this?

Thanks in advance,
Aletheia

 

[Fishrrman]

Here's what I suggest you do.
Print this out and follow it carefully (check off as you go along).

1. Boot to INTERNET RECOVERY (this is NOT THE SAME AS "the recovery partition"):
Command-OPTION-R

If you're connecting via wifi you'll need your wifi password.
The internet utilities take a while to load, be patient.

2. Open disk utility.

3. Check to see if disk utility has a "view" menu (newer versions do, older versions don't).
IF you see the view menu, choose "show all devices".
(this is a VERY IMPORTANT step, don't miss it)
IF there isn't a view menu, just go on to the next step.

4. Now look at "the list on the left". The topmost item should be the physical hard drive inside the iMac.

5. Click on the line for the hard drive. Then click "erase".
Choose "APFS" with GUID partition format.

The erase should take only a short time.

6. When the erase is done, quit disk utility and open the OS installer.

7. Start "clicking through". The iMac will restart one or more times, and the display may "go dark" for a few minutes with no other indication of activity. Be patient.

8. When the install is done, you should see the initial setup screen (choose your language).

9. I wouldn't go further at this point. Just quit the setup program. If it doesn't want to quit on you, press and hold in the power on button until the iMac shuts off.
When it boots again for the new owner, he/she will see the setup screen.

Good luck.

 

[chenaletheia]

Hi Fishrrman,
Your instructions were very clear and everything worked. Thank you very much.