Reinstall Partition Error

[Kateeturner]

I really need help! I’ve inherited some iMacs from a previous teacher at my school. I’m trying to reinstall iOS as no-one remembers the passwords. As they’re so old they can’t be reinstalled through the internet. I’ve broke it please help!!!

 

[Kateeturner]

 

[Kateeturner]

 

[BrianBaughn]

I think you need to let us know what model iMac(s) you have there.

 

[MBAir2010]

the instructions are there, follow these and see if you can start the imac.
if the drive is les than 4GB there probably is no drive in the imac
the "OSx base system" is what is on the logic board and not a hard drive as this happened to me last week.
if the top drive is in the imac, not an external one,
you probably need to erase the drive, then reinstall Mavericks due to the log in password not available.
the key is the restart drive, i saw a white one covered, and the osxbase system, not a actual hard drive.

the sandisk might be a camera card for something that size that is in the back of the mac.

 

[Kateeturner]

I have restarted and erased the drive. I’m just trying to get to a position where I can install mavericks from the usb installer i made. I’m not sure what model but I would guess late 2010/early 2011

 

[MBAir2010]

I have restarted and erased the drive. I’m just trying to get to a position where I can install mavericks from the usb installer i made. I’m not sure what model but I would guess late 2010/early 2011

is the usb mavericks a disk image?
and
the drive needs to be mac journal formatted.

there is internet recovery, but that will install catalina probably.

i had issues with a mcamini last week that drove me nuts, and i had to remember everything allover again!

 

[Fishrrman]

Something seems wrong here.

If you booted from the USB flash drive, and then "erased" the internal drive, there would not be a "recovery partition" on the internal drive (yet). (as seen in your images posted above)

Here's what I suggest you do (maybe you tried already, but I'll suggest anyway):
1. Power down, all the way off.
2. Press the power on button and hold down the OPTION key continuously to invoke the startup manager.
3. Select the USB bootable flash drive and hit return.
4. It will probably take a while to start up, but you should eventually see the OS installer.
5. DO NOT RUN THE INSTALLER YET. Instead, quit it.
6. Open disk utility.
7. Look at "the list on the left".
8. You want to click on "the top line" that represents the physical drive inside
(1tb WDC WD1001FALS...)
9. Now click the erase button.
10. Erase to "Mac OS extended with journaling enabled, GUID partition format"
11. When done, quit disk utility and re-open the OS installer
12. Try installing again.

Follow this routine exactly as presented.
Does it change anything?

 

[Kateeturner]

Something seems wrong here.

If you booted from the USB flash drive, and then "erased" the internal drive, there would not be a "recovery partition" on the internal drive (yet). (as seen in your images posted above)

Here's what I suggest you do (maybe you tried already, but I'll suggest anyway):
1. Power down, all the way off.
2. Press the power on button and hold down the OPTION key continuously to invoke the startup manager.
3. Select the USB bootable flash drive and hit return.
4. It will probably take a while to start up, but you should eventually see the OS installer.
5. DO NOT RUN THE INSTALLER YET. Instead, quit it.
6. Open disk utility.
7. Look at "the list on the left".
8. You want to click on "the top line" that represents the physical drive inside
(1tb WDC WD1001FALS...)
9. Now click the erase button.
10. Erase to "Mac OS extended with journaling enabled, GUID partition format"
11. When done, quit disk utility and re-open the OS installer
12. Try installing again.

Follow this routine exactly as presented.
Does it change anything?

There was no GUID partition format options, however when I try to erase the disk I get this error:

 

[Kateeturner]

 

[Fishrrman]

Re the unmount error...

Leave disk utility open for the moment.

Try dragging the icon for the internal drive into the trash using the mouse.

Does it disappear from the desktop?
But you still see "the top line" (for the drive) in disk utility?

If so, click on the top line NOW and try the erase button again.

SOMETIMES this can work.