hdmi plug after boot raspi 3 b how to resize screen

[hieuabc]

Hi, if i plug hdmi screen (hp pavillion 23xi) after boot/raspberry pi 3, screen resolution is very small, arandr doesnt allow to change it, so 600/400 instead of maximum 1920x1080. Is it possible to change resolution, without reboot?

[DuckHP]

Not sure since i've not experienced the problem.
But in case you haven't already, try:
$this->bbcode_second_pass_code('', 'xrandr -s 1920x1080
# 'DISPLAY=:0 xrandr -s 1920x1080' (if using SSH or TTY)')
in a terminal or tty. Which should to set the resolution to 1920x1080
if not, get some info by typing just:
$this->bbcode_second_pass_code('', 'xrandr
# 'DISPLAY=:0 xrandr' (if using SSH or TTY)')
which might give you some clues as to what might be going on.

notable links:
https://wiki.archlinux.org/index.php/Xrandr
https://wiki.archlinux.org/index.php/Xrandr#Resolution_lower_than_expected
https://linux.die.net/man/1/xrandr
https://www.archlinux.org/packages/?name=autorandr (sets resolution(s) automagically upon device(s) plugin/plugout)