BRICKED MBP Cant reinstall mac os, network install doesnt work, usb install isnt offered.

mackbl wrote:

Can't reinstall mac os after erasing disk. MBP 2018

Once the internal SSD has been erased on a 2018+ Mac, then you will not be able to boot to a USB drive since there is now way to authenticate especially if you did not previously modify the Mac's security settings using Startup Security Utility to allow booting from external drives. I'm not sure if the system will retain those settings once the internal SSD has been erased.

With a 2018+ Mac, if you have issues reinstalling macOS, then you may need to "Restore" the firmware which will reset the T2 security chip & firmware. The Apple documentation says that afterwards you will need to use Internet Recovery Mode to reinstall macOS although I thought I had a 2018+ Intel Mac have the OS pushed onto the internal SSD during the process...perhaps it depends on the version of macOS. Unfortunately a firmware "Restore" requires access to another Mac running macOS 12.4+ (at least the last time I check, unfortunately Apple keeps increasing the OS requirement for the host Mac).

I made a bootable flash drive for mac os 10.12 using my pc with Transmac (i dont have a second mac) but the macbook doesnt give me the option to boot from it no matter how many tutorials i follow

First I believe the 2018 model requires macOS 10.13+ so a 10.12 USB installer won't work. Plus I have not seen any success stories on these forums for using TransMac in recent years (Apple changed their installers a while ago). Unfortunately the only successful way of creating a macOS USB installer is by using a compatible Qualifying Mac and the instructions in this Apple article:

Create a bootable installer for macOS - Apple Support

Installing on a drive that requires MacOS Extended is getting more and more tricky. Apple thought users would be confused by all the APFS containers, so they hid that stuff by default, and that has ended up being FAR more confusing than than just letting it all hang out.

In Disk Utility, you need to able to see the DEVICE, identified by its immutable manufacturer-provided device-name. it is NOTHING like Macintosh HD, a name set by a person.

There is a tiny menu in the upper left corner. Make sure it says "show all devices".

then select the drive by its manufacturer name and completely ERASE. Use the default GUID partition scheme and MacOS Extended (journaled) if given a choice. NOT case-sensitive.

THEN your drive can be seen as a good place to install MacOS High Sierra.

so sorry, I missed that your mac is 2018 model with T2 chip. My advice was great for Macs that do NOT have a T2 chip.

HWTech has the correct advice for your 2018 MacBook Pro..