iMac 2011 Big problem when tried reinstalling the OS

[kanter]

Hi I am new to the forums, hoping someone could give me some advice.

I have a 27 inch 2011 iMac that I have been trying to totally wipe the OS by erasing it with Command + R. It has a 2TB drive in it and the problem is that at the end the erase hard drive hangs on last bit for hours on end. I (probably stupidly) held down the power button and tried doing it again.

Since then every time all that has happened is the Apple logo comes on and the cog constantly spins.

Holding the command key on startup cog spins then eventually brings up a blank screen. If I press the C key with a CD in there it starts making CD reading noises for a few minutes then does nothing - the cog just spins forever.

I am really worried that I have totally messed this thing up forever and dont want to have to start taking it apart at all if possible.

Any help is greatly appreciated!

Thanks

 

[macthefork]

It that's a mid 2011, it likely came with Snow Leopard installed. Have you tried holding down the Option (ALt) key when booting? This should give you a selection of either the original OS Snow Leopard Disk, or if the Recovery Partition is still valid (if you updated from Snow Leopard to a later OS) that should also show.

Do you have a backup, such as a clone or time machine? If either of these are connected when you boot holding the Option key, they too should show up as a selectable restore point.

 

[kanter]

Thanks for the reply

Holding the option key shows only the Recovery 10.8 disk and the CD I have in a DVD-R of Mountain Lion - clicking either results in a spinning cog that never changes. The CD makes a lot of weird noises for few minutes then gives up and cog just spins

 

[macthefork]

If Command + Option + R at boot doesn't bring you to internet recovery, you can try the following.

If you still have the Snow Leopard Disk that came with the iMac, try booting from that. If you can, then you can go to the Disk Utility from there and properly format and erase the HDD.

It's difficult to create a bootable Mountain Lion Disk, because the OS need to write to it as it's booting. (It can be done following a strict set of guidlines. However I've found it doesn't work more than it works. That's why it's best to create a bootable Flash Drive)

 

[kanter]

Trying network recovery now, thanks very much, did not know about this option, but cog just spins again.

My snow leopard disk causes a crash when I try to boot to it. And also mine came with Lion as standard.

I am going to try usb booting, but I have a feeling I am going to end up seeing the spinning cog again!!

 

[Weaselboy]

And also mine came with Lion as standard.

If you are positive it came from the factory with Lion, and you have applied all firmware updates, you should have the firmware based Internet recovery in place. To access that hold command-option-r when you boot. You will see a spinning globe after you access wifi while the recovery utility downloads.

Once the recovery screen comes up, start Disk Utility and select the drive brand name at the top (like Seagate 500GB or whatever) then erase the entire drive as one Mac OS Extended partition. When that is done quit Disk Util and click reinstall OS. That will download and install Lion from Apple's servers.

What prompted you to do this to begin with if I may ask? That spinning when try to access the hard drive almost sounds like you have a bad drive.

If what I described won't format the disk, try a disk repair from the same Disk Util screen in Internet recovery and tell us what that says.

 

[kanter]

Internet recovery does start up get the spinning globe and then it just goes back to spinning cog.

Must be a bad hard drive then. I was erasing the disk because the hard drive had become very slow in bootcamp

 

[Weaselboy]

Internet recovery does start up get the spinning globe and then it just goes back to spinning cog.

Must be a bad hard drive then. I was erasing the disk because the hard drive had become very slow in bootcamp

Yep.... sounds like a bad drive.

 

[kanter]

thanks anyway