santanarulez wrote:
Let me clarify. A friend of mine downloaded MacOS Sonoma for bootable USB drive for Intel chipset and shared it with me in a private web drive (we live far away).
Sometimes files don't arrive correctly after being uploaded & downloaded through some online file services. Just something to keep in mind if the installer has a problem running. You neglected to say what exact issues you encountered when trying to reinstall macOS with various methods. We need details on what you did and what occurred including the error messages.
Step 1
I would like to format my MB Pro mounting the HD onto the MB Air. The formatting process shouldn't be related to the architecture, should it?
Why? You need to install macOS anyway, so just use the macOS installer to do it. Either Internet Recovery Mode, or a bootable macOS USB installer will work. Although with a 2018-2020 Intel Mac with a T2 security chip may not allow you to use a USB installer if you never modified the security settings to allow booting from USB prior to erasing the internal SSD. In that case, Internet Recovery Mode is your only option. You can try to use Command + R to reinstall the OS that was just erased, or Command + Option + R to try to install the latest version of macOS that is compatible with your Mac.
What is the exact model of your Intel Mac that needs to have macOS reinstalled? You can get this information by entering the system serial number on the check cover page here (please don't post the serial number on the forum since it is considered personal information):
Check Your Service and Support Coverage - Apple Support
Step 2
I want to use this solution:
Create a bootable installer for macOS - Apple Support (LB)
to "install" the installer on my MB Pro. As I may understand, the solution above shouldn't create a bootable installer related to the architecture.
Alternatevelly, I could create the bootable installer on my USB Drive.
You want to create a bootable macOS USB installer using a USB drive or USB stick. You do not want to create a bootable macOS installer on the laptop's internal SSD. You will just end up with issues afterwards. Follow the instructions in the Apple article you linked by using a USB drive or USB stick.
You can use your M-series Mac to create the bootable macOS Sonoma USB installer which can be used on the Intel Mac (assuming the Intel Mac is compatible with Sonoma). And assuming that booting from USB was enabled prior to erasing the internal SSD.
Step 3
Startup my MB Pro with "Option" key e install MacOS by the HD or by the USB Drive.
What do you think about?
If you have a 2018-2020 Intel Mac with a T2 Security chip, then installing macOS to an external USB drive won't work unless you previously modified the security settings of the T2 Mac to allow booting from USB using the Startup Security Utility. Once the T2 Mac is erased, it is impossible to modify that setting until after you have reinstalled macOS to the internal SSD since it requires authenticating to a valid macOS admin user account. With an erased internal SSD, there is no longer any admin users to authenticate.
