fjd wrote:

You cannot type 'w', 'r', 'y', 'u', 'o' and return key. I haven't checked if capitals are affected or if non-alphabeticals like '$' or '=' are affected. It's got an American keyboard.

The problem is present when you boot direct to BIOS/UEFI.

All I want to know are likely causes. I don't propose to fix it if it involves hardware replacement.

So why would such a thing occur? I've never encountered this failure mode before.

That would be a dead keyboard.

Despite your mention of not fixing it, I think you should know
that keyboards are generally cheap and easy to replace. In this
case,

https://www.amazon.com/Replacement-Keyboard-UX330UA-AH54-UX330UA-AH55-UX330UAK/dp/B08LG1SN1V
is $35, and replacement would take ...

https://www.ifixit.com/Guide/Asus+Zenbook+UX303L+Keyboard+Replacement/53551

35 screws. No, I wouldn't bother fixing this. Attach an external
USB keyboard, copy all the data off, wipe the disk and send to
electronics recycling.

-dsr-

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)