Mac doesn't boot at all anymore.

josiajohn wrote:

Hi,

So, I formatted the disk of my macbook by putting it in target disk mode and then using disk utility on another mac. Now, of course, it doesn't boot anymore. The problem is that it doesn't boot into recovery mode either. Internet recovery just leads me to a picture of a globe with an exclamation mark. I've also tried to install macos, again by putting it into target disk mode but the installation program doesn't allow installations on macs in target disk mode. So I installed macos on an external drive but I couldn't boot from that either. (probably because of the security chip preventing booting from external drives)

Is there any hope that I can reinstall macos?

Well you could certainly help your self by stating what exact Mac this is...

ref:

About Startup Security Utility on a Mac with the Apple T2 ...

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-an-intel-based-mac-apdebea5be51/mac

https://support.apple.com/guide/apple-configurator-2/revive-or-restore-a-mac-with-apple-silicon-apdd5f3c75ad/mac

What year MacBook Pro?

Maybe this:

About macOS Recovery on Intel-based Mac computers - Apple Support

I would try using the other Mac creating a bootable USB install media and booting from that and try to install macOS.

Apple’s instructions

How to create a bootable installer for macOS

Here is how to get earlier macOS version

How to get old versions of macOS - Apple Support