New SSD (restored from TimeMachine) not detected internally — but is detected externally

[Pri-UK]

Hello — hope to get some advice. I have a mid-2011 21.5 inch iMac running on High Sierra and I attempted to replace the HDD with a new 2TB Crucial SSD (CT2000MX500SSD1) but am experiencing a non-detection error — an alternating question mark folder icon with the Apple logo and a cross icon.

These are my steps:
1. I removed the original 500GB Seagate HDD from my iMac and attempted to fit the SSD directly into the space (straight from the packaging without doing any preparative work) utilising a new thermal SATA cable and 2.5" to 3.5" mounting kit
2. I then rebooted and hoped to see the new SSD to perform a restore (tried holding down the Option key (for the startup manager) and again with Command+R (for recovery)) but couldn't see it
3. I opened the iMac again and double-checked the internal connections to the SSD with the SATA thermal sensor, data and power cables but they were nicely connected and I rebooted but still got the same issue
4. I took the SSD out of the iMac and used my 2018 MacBook Pro to erase and format it with the Mac OS Extended (Journaled) option
5. I then tried refitting it again in the iMac and rebooting. Still no joy
6. I tried again without going via the thermal sensor SATA cable but instead going directly with the iMac SATA cables — still no use.
7. I then decided to use an external caddy for the SSD to connect to the iMac via USB where I could successfully initiate an internet recovery to install MacOS and then do a TimeMachine restore
8. Whilst it was connected externally via the caddy it booted up okay and I could use the iMac as normal — but obviously I want to install it internally
9. I then opened up the iMac again and tried to install the SSD, rebooted and it failed again
10. I then put the original 500GB HDD back in to check I hadn’t accidentally damaged the cables / sockets but it booted up fine. I then swapped it back with the new SSD but again got the non-detection issue

Not sure where to go next — so would welcome any suggestions.

On a side note, I'm not sure if this is related, but might be worth mentioning. When I tried to boot up externally with the original HDD using the caddy, the iMac wouldn’t detect it, but it did detect the old HDD internally — and as mentioned, the caddy works fine booting up the iMac with the SSD.

Thanks in advance for any assistance.

 

[Juicy Box]

Check your firmware and see if it is current.

 

[Juicy Box]

You can check firmware by going to the Apple > About this Mac > System Report > Hardware > Boot ROM Version.

Then either look it up or post it here.

 

[Pri-UK]

It's 87.0.0.0.0 — which looks like it's the latest version based on:

Which EFI firmware should your Mac be using? (version 3)

Apple doesn’t provide an official list of the current EFI firmware versions which should be installed on each model of Mac. Until 30 October 2018, it provided usable version numbers in System…

eclecticlight.co

 

[Juicy Box]

I had the almost exact issue that you have, except I had the SSD in a 3.5" caddy.

It turned out that I had not seated the SSD in the caddy very well, and basically there was no connection being made.

Considering you connected the SSD directly to the OEM SATA cable, and it still isn't working, I am unsure of what it could be. Maybe someone else might know.

 

[Pri-UK]

Thanks — actually, I meant that I tried connecting directly to the OEM SATA cable not via the thermal SATA cable but still through the 3.5" caddy. Although I can see it okay when using the external USB caddy so the connection should be secure.

Do you remember what format you used to format the SSD? I used Mac OS Extended (Journaled), but I wonder if I should have selected APFS...?

 

[Juicy Box]

If you boot from your OEM drive connected externally, can you see the internal SSD in Disk Utility?

Thanks — actually, I meant that I tried connecting directly to the OEM SATA cable not via the thermal SATA cable but still through the 3.5" caddy. Although I can see it okay when using the external USB caddy so the connection should be secure.

Try connecting directly from the SSD to the OEM connector, bypassing the thermal cable adapter and caddy. You can just let it sit in there while you test it, or maybe put a piece of tape holding it on.

The SATA cable with the thermal sensor is kind of bulky and maybe it just isn't seating well.

Better just to eliminate possible problems.

Do you remember what format you used to format the SSD? I used Mac OS Extended (Journaled), but I wonder if I should have selected APFS...?

This shouldn't matter, either is fine.

 

[Pri-UK]

Cool, thanks — will give it a whirl.

 

[Pri-UK]

Wow, you nailed it. I connected directly, taking the caddy off, and it works fine. Big step forward. Don't really understand as the 3.5" caddy to external USB caddy works. How did you manage to seat it properly in the 3.5" caddy? I screwed the SSD in so I'm unsure how to get a tighter fit...

 

[Juicy Box]

How did you manage to seat it properly in the 3.5" caddy? I screwed the SSD in so I'm unsure how to get a tighter fit...

Maybe post your caddy? The ones I like to use are tool-less.

I usually reseat stuff like that by removing it, blowing some air in the female side to make sure there is nothing caught in there, and fully slide in with some pressure a few times.

Maybe it was just barely seated, that is why it worked via USB, but not internal.

Maybe there is some HW incompatibility issue.

Maybe the cable wasn't fully seated.

 

[Juicy Box]

Also, you could just go without the caddy. Use double face tape and tape in in place. Or use a caddy without a SATA connector, as it isn't really needed with this Mac since it uses SATA cables.

 

[Pri-UK]

Thanks big time — just fixed it in with some electrical tape, which should hold it in. Do I need to worry about it making contact with the internals? Not sure if the caddy's purpose is to prevent that. Anyway, it's booted up fine and running amazingly zippily — not sure it was ever this fast! Really appreciate your help!

 

[Pri-UK]

Maybe post your caddy? The ones I like to use are tool-less.

This is the caddy I used — guess I'll just send it back:

SABRENT 2.5" to 3.5" internal hard drive adapter, converter mounting frame, 7 | 9.5 | 12.5 | 15mm SSD & SATA adapter, SSD mounting bracket compatible with desktop and servers (BK-PCBS)

SABRENT 2.5" to 3.5" internal hard drive adapter, converter mounting frame, 7 | 9.5 | 12.5 | 15mm SSD & SATA adapter, SSD mounting bracket compatible with desktop and servers (BK-PCBS)

www.amazon.co.uk