Imac 2011 high sierra not longer booting

[lhoffstadt]

Hello everyone,

I need to ask for some advice please, I have a Imac 27 inches 2011 that was running High Sierra and I turn it on the other and it stop booting. It tries to boot and then turns off. I started on verbose mode and got an error message for the disc so I did a repair on the disc under Single user mode and after a reboot I was able to access the disk utility.

Over there I'm able to see Internal diskOs2 that is the one I repair in single user mode
Also I see another disc "disk images OS X Base system where I can see the amount of space of the disk, how much is avaiable and it's mounted".

Any recommendation please on how can I recover the information I have on the disc.
Is there a way to recover the date I have on the disk?
Is there a way to recover or reinstall the OS?

Or is best to mount an external SSD drive and do a refresh install over there of the OS and use the internal disk as storage?

Any recommendation would be greatly appreciated.

Thanks so much.
Luis

 

[Nguyen Duc Hieu]

How to recover data from your internal disk:

1. Open the iMac (search Youtube for a guide video) and take out the spinning HDD.
2. Take it to a professional data recovery service.

After removing the HDD, try to boot it without any SSD/HDD installed to verify whether the issue still persists. If the iMac is still functioning, you will see finally a greyish white screen with a folder icon + question mark at the center.

How to re-install Mac OS.

1. Install a new blank SSD to the place you have just remove the old broken HDD. 1 2.5" SATA SSD + 1 3.5" to 2.5" adapter., or just simply keep the SSD in place with only 1 screw.

2. Do an Internet Recovery. Google for Intenet Recovery

 

[Fishrrman]

OP:

Be aware that 2011 iMacs with dedicated GPU's had a history of failure of those GPU's.

It could be that...
... or... it could be the internal drive is going bad on you.

WARNING:
"Professional data recovery services", as Nguyen mentions, are VERY expensive.
By very expensive I mean many hundreds or even thousands of dollars. You probably don't want to spend that.

I would like to suggest two other startup routines you can try.

First, try a "safe boot".
From power off, hold down the shift key and KEEP HOLDING IT DOWN.
Press the power on button and KEEP HOLDING the shift key down.
Does it boot?

WHY I asked you to do this:
When you do a safe boot, it "bypasses" the discrete GPU and uses the CPU's "internal" graphics. If there are GPU problems, you can still get booted and running this way.

Next thing to try:
Try booting to INTERNET recovery.
This is NOT THE SAME as "the recovery partition".
From power off, boot up pressing down:
Command-OPTION-R
Again, keep holding these keys down for a while as the Mac boots.

If you're using wifi, you may be asked for your wifi password.
Enter it.

Does this work?
Do you get to the internet utilities?

If so, open Disk Utility.
Go to the "view" menu and choose "show all devices".
Now look at the list on the left.
It should show you the internal drive and partitions on it.
I suggest you click on EACH ONE (starting at the top).
Then click the "first aid" button and see what report you get for each one.

PRINT OUT this post for reference.

 

[lhoffstadt]

thank you , I will do that and report back