Installing SSD in late 2015 iMac issue

[tackit]

I have a late 2015 27" iMac and bought a Samsung EVO 500gb SSD to replace the original 1TB drive. I also got an enclosure. I was able to erase the SSD drive and install Sierra without any issues and use the drive just fine from the enclosure via USB 3.0.

I then decided to open up the iMac and install the SSD with the OWC cable. All went fine, but when I try to boot it up, it will show the no entry sign and flash the Apple logo as though it's trying to boot up, but will not actually manage it.

I'm currently having to use the old HDD in the enclosure until I find out why.

I have not stuck the screen in place yet.

HELP!

 

[nambuccaheadsau]

'The OWC cable'.

Does this refer to the heat sensor kit required with 27" iMacs, or the SATA cable? Changing hard drive always pays to replace the cable as time and heat m akes it extremely brittle. Here is a tear down from ifixit for that model and covers everything:-


https://www.ifixit.com/Guide/iMac+Intel+27-Inch+Retina+5K+Display+SSD+Replacement/30537

 

[tackit]

I fitted the short heat temp cable with stick on sensor for the drive.

The computer is almost new and not been used much at all, like only a few months, I cant believe it's the SATA cable.

 

[Fancuku]

Why did you add that cable? I believe that cable is no longer needed if you run El Capitan or Sierra.

 

[tackit]

I used it as when researching the job, I found I needed it. Maybe that info was incorrect.

 

[nambuccaheadsau]

You need it on 27" iMacs still, not the 21.5".

 

[Zilthy]

When you boot from the old drive in the enclosure, with the new SSD installed, do you see the new SSD in Disk Utility?

 

[tackit]

When you boot from the old drive in the enclosure, with the new SSD installed, do you see the new SSD in Disk Utility?

Yes it was visible, but I've installed the original HDD and sealed it up and do not plan on opening it up again now. I'm happy using the SSD as an external via USB.

Thanks for the replies.