I just got a used Surface Pro 3 for my wife -- her only real requirement for a computer is that it runs Linux and my initial research told me that it would be a piece of cake getting Fedora to run on it.

Alas. Not so.

I've tried various distributions; Fedora 23, 25, 27 and 28-beta1, as well as Ubuntu and Manjaro. Grub boots just fine on all of the install media, but once I try to start the live distros, the machine fails to boot properly; this happens in various ways.

Fedora 25 will boot the kernel and will just print
"efi_boot() failed
efi_main() failed"

All of the other options will load the kernel and initfs and proceed to boot that part OK. Once it comes to mounting the root, the system complains that the device wasn't ready within 30 seconds.

I suspected that the reason for the error was a faulty USB device, so I tried a few different ones -- all with the same result.

I now suspect that the UEFI firmware will not make the entire USB device available, or that it will somehow make do so wrongly; both are problems I don't know how to fix.

I've tried to find others with the same problem, and there appears to be a few, but I have yet to find anyone who can help.

While the machine was cheap compared to getting a new one, it's not cheap enough to just keep around as a paperweight (especially considering that the only paper I keep around are my daughter's drawings).

Two things that should help.

Since the Surface Pro 3 with Windows 8 is a uefi machine you will have to 'disable' the secure boot and the quick boot in the BIOS.

The other thing is (if you haven't already) to change the boot order so that when the machine boots it will go to usb if that's how your trying to run Linux Live.

https://www.zdnet.com/article/instal...e-a-refresher/

I'm not sure what is going on with the 'efi boot failed' I think that is referring to a efi partition.

Ubuntu and Linux Mint are uefi friendly distro's so you may want to try them instead of Fedora.

How are you making the usb bootable? Are you using Rufus?
https://rufus.akeo.ie/

may we assume that the usb sticks will boot properly on some other device?
in other words, have you checked that they work?
how have you created them?

btw, you might want to concentrate on 1 distro for the duration of this topic; makes it much easier to troubleshoot.