2015 iMac Will Power On, Won't Boot& Backing Up In Recovery Mode

To backup your computer you will need a freshly formatted hard drive at least large enough to hold all the occupied space on your internal drive. This is what you will do:

Clone Yosemite, Mavericks, Lion/Mountain Lion using Restore Option of Disk Utility

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

1. Select Disk Utility from the main menu then press the Continue

button.

2. Select the destination volume from the left side list.

3. Click on the Restore tab in the DU main window.

4. Select the destination volume from the left side list and drag it

to the Destination entry field.

5. Select the source volume from the left side list and drag it to

the Source entry field.

6. Double-check you got it right, then click on the Restore button.

Destination means the external backup drive. Source means the internal startup drive.

To erase the drive and reinstall OS X you will do the following:

Install or Reinstall OS X from Scratch

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Erase the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.

2. After DU loads select your startup volume (usually Macintosh HD) from the

left side list. Click on the Erase tab in the DU main window.

3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on

the Security button and set the Zero Data option to one-pass. Click on

the Erase button and wait until the process has completed.

4. Quit DU and return to the main menu.

Reinstall OS X: Select Reinstall OS X and click on the Install button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible

because it is three times faster than wireless.

This should install the version of OS X that you had installed.

Select the volume that is ghosted and click on the Mount icon in the Disk Utility toolbar. The volume should also now appear on your Desktop. If you cannot mount the volume, then there is a problem. You will need to boot to the Recovery HD and run Disk Utility. Select the volume entry and click on the First Aid tab in the main window. Click on the Erase button. You should then be able to reinstall OS X.

You cannot do anything if the volume won't mount but you can certainly give it a try. Cloning to another drive involves unmounting the volumes, so it may work. Worse that can happen is it won't work. If you are able to clone it, then you will need to try repartitioning and reformatting the drive, but to do that means you have to boot the computer from an alternate drive such as an external bootable drive.

But if I were you I would take the machine back where you bought it. It is still in warranty. You should let them fix it under warranty in the event there is a hardware failure.