imac 27" 2011 wont start up

[koden]

Hi

I have this old imac.
I have removed harddisk and placed a SSD instead.

Inserted USB with high sierra OS.

holding ALT down while starting to boot from the USB.

Click install high sierra..
It starts and tell me there is 30 min left but ends 90% finish and stucks there.

NVRAM have been reset. Did not help.

I tried safe mode holding shift down.
Then I got into the OS high sierra ?????
Where did that come from?
And safe mode.. how does that look.
Could not see any diff. from normal OS

Before all this I started with disk utility and created new partiton.
At first step in utility I saw that file system was APFS
But at partition I could choose journaled and I did and created a partition.
Which I then tried install to as written above.

 

[vkd]

Sounds to me like the APFS/journaled partitioning has created a mixup. If it was me, I'd boot from the USB installer again, then when it loads the GUI, start Disk Utility from there and erase the drive completely, re-partition it again with Journaled but making sure that there is no indication of APFS being selected at any point, then close Disk Utility and continue with a fresh installation.

 

[koden]

hi
I have tried delete SSD disk completly
Create new one and install

I have tried another SSD disc

I click install high sierra and it starts and tells me 30 min.
After the 30 min i stops at 90%
See picture.

Next I could try is another installation media.
Or could there be something else wrong?

 

[davegoody]

Hi

I have this old imac.
I have removed harddisk and placed a SSD instead.

Inserted USB with high sierra OS.

holding ALT down while starting to boot from the USB.

Click install high sierra..
It starts and tell me there is 30 min left but ends 90% finish and stucks there.

NVRAM have been reset. Did not help.

I tried safe mode holding shift down.
Then I got into the OS high sierra ?????
Where did that come from?
And safe mode.. how does that look.
Could not see any diff. from normal OS

Before all this I started with disk utility and created new partiton.
At first step in utility I saw that file system was APFS
But at partition I could choose journaled and I did and created a partition.
Which I then tried install to as written above.

I would, from experience of my older Macs, leave it running overnight. I remember installing HS to a mac of a similar vintage with a new HDD (not SSD but same applies, only slower), and it taking HOURS. It may well eventually finish. Patience is key.

 

[koden]

I would, from experience of my older Macs, leave it running overnight. I remember installing HS to a mac of a similar vintage with a new HDD (not SSD but same applies, only slower), and it taking HOURS. It may well eventually finish. Patience is key.

Ok will try that

 

[koden]

2 days at 90% and I shut it down :-(

have tried google on it..
A lot of errors with installation stuck
But not any like mine.

What happens is when choose install I choose my new disk created.
High sierra starts installing telleing me there is 30 min.
after something like 20 min there is 1 minute left, and it finish the bar.

But then the grey bar starts from beginning and with no time estimat.
it runs quikly up to the 80 or 90% and just stops there.

I have some idea about that my disk and partitions are wrong...

I have choosen show all disks in diskutil.
marked the upper one with name of disk manufactor.
Erased and choose GUID and journaled file system
named disk MAC
and erase

It create a disk underneed the disk manufactor disk.

It's this MAC disk I choose when I install (no other to choose).

 

[Fishrrman]

Use a DIFFERENT working Mac to install a clean copy of the OS onto an external USB3 drive.
Set this drive up so that it's bootable "to the finder".

Then, take that drive and connect it to the problem iMac.

If it still won't boot, it could be a bad GPU inside.