Thankyou for your reply! All good.
ASUS has a thing to insert USB and hold ESC before powering. Then USB boot is available.
Re installed. Back up and running. Thanks again.
I have the same problem. Asus s56ca-xxo15h
Linux Mint Cinnamon 19
Ran for several weeks then crashed. Cannot rescue boot.
It will not boot via USB. Help please.