Moving External SSD to Internal SSD _ 2015 27" iMac

[PeacefulMan]

I have a 27" 2015 5K iMac that I bought without an internal drive. So I bought a 1TB WD SN770 with an external enclosure and followed Apple instructions to install MacOS and plugged it on the outside via a USB and it's working. I can start the computer and do stuff.

Can I now simply shut the computer down. Remove the 2280 blade out the enclosure, open the mac, simply insert it in its slot, and that should let me use it as before without doing anything else? I prefer to have the SSD inside.

Thank you!

 

[DeltaMac]

well, yes, in theory... But, in reality, the task is not simple.
( I laughed when you said "...without doing anything else?" making it sound like a 5 minute job. hint: It's not!)
Maybe you will rethink your idea about making the drive internal. I have done it 5 or 6 times, so have some experience. I would not tell anyone it is a simple job - it is not - but it is doable.
Watch a YouTube video for installing an NVME stick in a 5K iMac, or read through the steps for that task.
iFixit.com has good repair steps:

iMac Intel 27" Retina 5K Display Blade SSD Replacement

If your iMac was configured with a solid state drive or Fusion Drive, it includes a blade SSD on the back of the logic board. Use this guide to...

www.ifixit.com

- Note that you have to cut through the tape that holds your iMac together (Yes, it's double-sided tape, no screws to get inside.) You can order the tape kit to put your iMac together again, also from iFixit. Follow the steps carefully, and take your time.
Once you open the iMac, you have to remove several parts to get at the logic board. The blade slot is on the back of the logic board, so that has to be completely removed. You will also find that there is a slot for your WD blade, but the connector on the logic board is used only by Apple. You will need an adapter, such as one that Sintech sells. Go to Amazon for the Sintech Apple-to-NVME small adapter
Oh, yeah, also several fragile internal connectors where you have to be careful when opening those connectors.
Have I convinced you, yet?

 

[PeacefulMan]

Thanks for the quick reply, you're right I made it sound so easy .. Well I did check a bit about the process and I'm conscious that's it's not like I made it sound. My question was mostly about if I had to reload anything software or do any work on reprograming the blade. Or, it'll be simply a plug n play (with the extra hardware disassembly/assembly). considering that the blade has already some MacOS in it and it's booting up and working fine from the external enclose.
PS: for reference, I did previously inquire about related issues to this iMac here and here:
I also, already bought Apple adapters for the M.2 blade, one simple short and the other long where you can sit the entire blade on it, bought some thermal paste/pad as well.

Edit: I'm hoping to see some improvement in speed between external and internal. It might not as the theoretical 10x but probably noticeable (although it's not bad at all now!). USB 3.0 is Gbit/s (600MBps) while the blade can do thousand of MBPs. For comparison, I do have another couple years older 21" which still with Fusion HDD and is brutally slow! ,,, we're talking seconds to see the mouse moving and things happening....

 

[Fishrrman]

Just be sure you have A BACKUP before you open the iMac.

And be aware -- many folks have pried open their iMacs (thinking they could do the job), and have ended up with... a BROKEN computer.

Are you SURE you can do this?

 

[PeacefulMan]

Are you SURE you can do this?

Why not?
I don't have any data in it, so no backup needed. bought it recently and working on it.

 

[DeltaMac]

I forgot that you said that there was no internal drive. That means that someone opened the iMac to remove the drive.
That should mean that there is no normal reassembly, or double-sided tape. I did this once for a customer, and simply applied a strip of duck tape/gorilla tape to the outside edges, as a temporary measure until the owner decided to add another internal drive. I suspect it will be easy to open, unless someone was dumb enough to re-apply the normal tape kit sold to complete a real reassembly (with no drive inside...!)

 

[PeacefulMan]

I forgot that you said that there was no internal drive. That means that someone opened the iMac to remove the drive.
That should mean that there is no normal reassembly, or double-sided tape. I did this once for a customer, and simply applied a strip of duck tape/gorilla tape to the outside edges, as a temporary measure until the owner decided to add another internal drive. I suspect it will be easy to open, unless someone was dumb enough to re-apply the normal tape kit sold to complete a real reassembly (with no drive inside...!)

Yes the internal drive was removed and the screen was held with some tape on the outside, so I was able to lift the screen off to check quickly inside, didn't take the screen off entirely, just swung it few inches up and reconnected a couple cables because the screen was always dark even when I can here the fan going. After connecting the cables I was able to see the prompt and worked on it. I did buy a screen seal/tape. My other problem is what they call a stage light at the bottom?!... not sure it's fixable.