VID and PID were set. Can you elaborate on how you remove the boot options?
Both the original and the replaced extra.lzma result in that black screen. I tried a different USB Drive - no joy. Different port - same result. I don't think I got the PID/VID part wrong, as the drive would boot fine on other machines.
Can someone tell me what the option "set default" in grub.cfg would do? Will it let me pick the AMD option as the standard option, so it would try to boot this without my interaction?
Might sounds silly, did u double check your bios that u boot from usb at 1st priority. if u not even see the loader's menu,i think it won't make any difference either u set default or not, even u load the intel version,u can still see the booting screen.