i got lost in your mail... but i do see from your subject that you should use `pacman -Syu` and not just `pacman -Su`, as the package database wont be updated without `y`...
and for blank screen, maybe try kernel option `nomodeset`... and in next mail try to be more precise what you did and what happens... as you talk about "pop-ups", did you install xorg ? are you using a DE ? which gfx driver you installed for xorg ?...
