iMac Pro iMac Pro will not start after rebuild

[Noot]

Yes, and apperently you also need AST (Apple Service Toolkit) for this:

https://theapplewiki.com/wiki/T8012#T2_Recovery_USB_Device_ID

 

[Regulus67]

I purchased a logic board, with Radeon Pro Vega 64x. Launched in 2019, so the last version.

This time I had no problem restoring the machine with Apple Configurator 2 in DFU mode.
But I am still trying to do Internet Recovery. Similar problem I had with the new 8TB SSD kit for the Mac Pro 7,1.
Will see if it will download macOS in the end. After who knows how many attempts.

I believe the other logic board has become locked or bricked. And I will have to bring it to an Apple technician. I am happy that there is no fault on the display, PSU or any other parts, at least.

 

[Regulus67]

Working on the logic board, and swapping parts is not hard when you done it several times 🤣
Upgrading the CPU or memory should be fairly easy for anyone who is careful.

But the T2 chip prevents one from upgrading or swapping the SSDs easily. If one could have used a bootable USB it would have been so much easier.
And that is only possible after a user with admin rights has been created. With the option to change boot security, and allow booting from USB. To install an older macOS for instance.

Internet Recovery is a problem. I do not know what Apple is doing with its Recovery server.
And as far as I can tell from my attempts. It does not offer other than the latest macOS. And it is very difficult to get a stable connection. It tends to cause errors after about 15 mins. It downloads about 300 MB and then stalls.

I have a 1 000 Mbit/s fiber connection

 

[Regulus67]

 

[PaulD-UK]

Hi, is there a reason you aren't using a wired ethernet connection?

A search for error -2003F/-2004F comes up with this:

"The most common cause of... error -2003f is an unstable internet connection. The error message is usually accompanied by an image of a globe with an exclamation point icon over it, indicating a problem with the connection. That unstable connection is likely to be at your end. So, it could be a problem with your Mac’s Wi-Fi, your router, or your broadband provider. It’s less likely to be a problem with Apple’s servers.
...with an ethernet socket, connect that to your router...
That should be a more stable connection than Wi-Fi.
Reset NVRAM..."

Apple has a support document that deals with errors 2002 and 2005, which both refer to the same networking problem, but with USB connectivity rather than WiFi.

 

[Regulus67]

Hi, is there a reason you aren't using a wired ethernet connection?

I am trying both ethernet and wi-fi. Both are having issues. Although the ethernet should be far better.
I normally use only ethernet, with wi-fi reserved for my iPhone and iPad.
But with Internet Recovery, I seem to have better luck with wi-fi. Had the same issue when I upgraded my Mac Pro 7,1.
It is weird

 

[Regulus67]

I have continued experimenting. Using ethernet, I looked at the router, and saw that it was basically idle.
And there was only the spinning globe.

Command-R

With wi-fi I get a progress bar. But it has timed out and given errors a lot of times. Also got a -2005F error.

Soooo close 🤣

I did end up trying Shift-Option-Command-R multiple times. Figured I might as well try that, if it fails anyway. And I prefer an older macOS version.

At last success. After having restarted the process multiple times, for the past 12 hours.

I can't believe it! In the process of installing macOS Mojave right now 🥰

-----

If you try this, and can't make the Internet Recovery. Keep at it. Restart and try again, and again, and again

 

[Regulus67]

This machine had 18-core, 64 GB memory, 2TB storage, and Vega 64. But it felt to hot in the exhaust, compared to my standard iMac Pro.
So I decided I should open it up. Remove any dust, and apply new cooling paste on the CPU and GPU. And upgrade the SSDs while I was at it.

It now runs cool, seems the temperature is normal when I check with my hand.
It has been quite a challenge. And I doubted this would end well. But it did !

It is quite possible I will install 128 GB memory, before I seal the machine up again.

 

[SnowPenguin]

Glad it worked for you. That machine must have cost quite a lot (at least when it was new)

 

[Regulus67]

Glad it worked for you. That machine must have cost quite a lot (at least when it was new)

Thank you. Yes they were very expensive new from Apple. The Vega 64x was +$700. I don't remember what the other parts added.
I purchased it very cheap, about $740. And I paid $706 for the logic board, with import duties (25%) from the US to Sweden.

I will try to let an Apple technician have a look at the original logic board with Vega 64. To see if it can be restored and functional again. If so I will install a 10-core, with 64 GB memory, 2 TB storage, and install that in my standard spec iMac Pro (base model)

 

[Danwanda]

Thank You for this Thread! I have the same problem after upgrading! Upgraded from 8 to 10 core , 1 tb. to 2 tb., 64mb. to 128 mb ram. I had no power either or video ! I rebuilt 3 times! I was ready to reorder the power supply, when I went to this forum! I tried the Apple configurator on my MacBook Pro to iMac Pro and it recognized it an did a restore and update! Now, the fan spin!! I replaced the screen and now doing a Recovery! Thank You so much!! I have taken iMacs apart all my life but, never an iMac Pro! I am new to it! But , after taking it apart 3 times, I can do it in my sleep!
Iphone 15 max.....Iwatch SE 2
iMac Pro 2017 10 core 3.3, 128 ram, 2 tb.
Imac 2019 3.7 6 core, 36 ram, 512 ssd -3 tb. sata drive.
Imac 2017 3.4 I5 , 16 ram , 1 tb.
Probox data center with 10 Terabyte storage for back ups!

 

[Regulus67]

... I replaced the screen and now doing a Recovery! Thank You so much!! I have taken iMacs apart all my life but, never an iMac Pro! I am new to it! But , after taking it apart 3 times, I can do it in my sleep!

I am happy to hear you were able to upgrade and do the recovery, on your iMac Pro. Well done 👍

 

[Terraaustralis]

I am happy to hear you were able to upgrade and do the recovery, on your iMac Pro. Well done 👍

Well done indeed!
Quite an education for us all.

Small point for future reference. Assuming your Internet is working, Download Mist from Github.

GitHub - ninxsoft/Mist: A Mac utility that automatically downloads macOS Firmwares / Installers.

A Mac utility that automatically downloads macOS Firmwares / Installers. - ninxsoft/Mist

github.com

It is a brilliant software app. which enables you to download and install any Mac OSX to any internal or external drive in one step. Much, much faster than Command R download and install. Plus you choose your OSX and drive so the installation happens in one step instead of several.