Boot fails after GRUB on Live USB, but Puppy Linux and Hiren's/Windows work

The type of failure which happens on all distros would indicate a hardware issue. Depending on the previous owner, it may not be treated so nicely and weird things can happen.

Maybe Secure Boot? But this wouldn’t let grub run in the first place.

For now I’m going to declare this probably a hardware issue, give up on installing Manjaro to disk, and accept the fate that this machine will boot to Windows. Maybe an admin/moderator can mark this thread closed. It would have been interesting to understand why Puppy Linux boots but Manjaro doesn’t boot.