Cannot boot to recovery

[Rhbiz]

I have a 2008 iMac and upgraded the hard drive to SSD and increased the ram to 6gb. I have also used the Mojave patch from dosdude1 which upgraded the operating system from El Capitan, it works well. I want to wipe the hard drive and reinstall before passing this unit on, but cannot erase the disk. I tried to boot from a USB drive because I'm told I cannot erase the disk I booted from, but that and the hard drive are greyed out too. The machine will not boot to recovery and so I'm stuck. Any suggestions?

 

[Bigwaff]

You need to install High Sierra first in order to update the boot rom to version which can boot off APFS disks. See “Important Note” under “How to use” section.

macOS Mojave Patcher

 

[Rhbiz]

Thanks for the response and advice, which I took. Regretfully High Sierra will not install because Mojave is already installed.

 

[Bigwaff]

I tried to boot from a USB drive because I'm told I cannot erase the disk I booted from, but that and the hard drive are greyed out too.

What version of Mac OS is on the bootable USB drive?

 

[Rhbiz]

Mojave 10.14.6

 

[DeltaMac]

OP has a 2008 iMac, which does not support High Sierra natively.
There's no updated ROM beyond El Capitan, so waste of time for a Mac that already needs a patched system to boot from Sierra or later.
If you want to erase the drive, boot to a native-supported system. Booting from an El Capitan installer will let you erase the drive. Disk Utility, select the top item in the drive list, which should be the internal SSD. Erase that device, and all will be gone (ready then to install a good system.)
I have one of those 2008 iMac (20-inch, iMac8,1), which has 3 bootable volumes: Leopard, El Capitan, and an OCLP install of Sonoma.

 

[Rhbiz]

Thank you, I will reinstall El Capitan as you suggest. Will it install with Mojave already installed which is a newer OS?

 

[DeltaMac]

I didn't get back to respond to your post. Did you have any problems erasing the boot drive, and installing El Capitan?

 

[Rhbiz]

Thanks for your help. No luck installing El Capitan. I cannot erase the boot drive it is greyed out. I cannot boot from a USB either. The option key is not connecting to the disk boot option. The command R function is not opening the recovery window. I am stuck

 

[Bigwaff]

I cannot boot from a USB either

With bootable USB device attached, hold down the “Option” key while starting the iMac. The Start Up Manager should appear. If your USB device does not appear as a selection, your bootable USB was created incorrectly or your USB port(s) could have issues.

 

[Rhbiz]

Thanks for the reply: The option key is not booting up to show either the internal hard drive or USB drive. Disk utility shows both disks however. I have reformatted the USB drive and made a fresh installer, which terminal states is good. So I'm still stuck. Each time I try to boot up to recovery, boot from USB or even safe mode, the computer just defaults to the Mojave OS already installed. The computer works well, but I can't erase the drive to pass on the computer to another user.

 

[Bigwaff]

What type of keyboard are you using? Perhaps you need a wired Apple keyboard or a wired keyboard which sends the special Apple key signals.

 

[DeltaMac]

Yes, you can't erase the drive that you are currently booted from.
You COULD erase after booting to internet recovery, but, unfortunately, a 2008 iMac cannot do internet recovery as it is too old...
Are you using a windows keyboard (from a PC, and would have the Windows key, instead of a command key)?
If that is what you have, the iMac would NOT see the alt key-- but, you should see the boot screen, if you start while holding the Windows key, NOT the alt key. The Option/Alt key, during boot (when software has no control), may only be seen correctly with an Apple-brand keyboard.

 

[Rhbiz]

No luck using the windows key, so I am getting a wired apple keyboard to try that. Thanks for your help

 

[Rhbiz]

What type of keyboard are you using? Perhaps you need a wired Apple keyboard or a wired keyboard which sends the special Apple key signals.

wireless apple keyboard and generic wired PC/Mac keyboard

 

[Rhbiz]

Thank you everyone: The problem is solved. I switched to a wired apple keyboard and mouse which allowed me to boot to USB. I then reformatted the SSD to APFS and installed El Capitan. BINGO! It worked.