AHT problem

crcaillouet wrote:

I am having trouble running AHT on my MacBookPro 2012, non-Retina, Mojave machine.

I get an error message that reads "Cannot Load EFI/Drivers/TestSupport.efi".

Any clues?

This error started occurring after Apple made a change to one of their system firmware updates so that the required file isn't accessible. You could try upgrading the laptop to Catalina to see if the system firmware update with Catalina will fix the issue. Maybe your laptop never installed the Mojave system firmware update properly. For some reason some Macs are just unable to boot to the Apple Diagnostics (this can affect booting to some other Apple services as well). Once a Mac has had the system firmware updated while running macOS 10.12.6+ the Mac should not require any drives to be attached in order to boot into the online Apple Diagnostics as it is now all done from firmware. I believe the error is actually referring to a system boot file on an Apple server (similar error also happens when trying to Netboot some of our organization's Mac to our Netboot server).

Try a PRAM Reset (hold the PRAM reset for at least three chimes). Sometimes the NVRAM can hold an incorrect boot setting that interferes.

Otherwise your Mac will no longer access the Apple Diagnostics.

That's a clue. When you replaced the drive did you copy the contents of the old drive or clone it? Copying doesn't always move the Recovery partition with the diagnotics; cloning does.

DId you hold d or did you do "command d" at startup. d without command is the right one for a pre-2013 model.

Did you replace the hard drive at some point?

Is the computer connected to the internet?