For some odd reason the Scroll Lock button doesn’t work in an Xsession in Ubuntu. There’s an old bug report here. However it works as it should in a virtual terminal. The interesting thing though is that Xev will detect the key press. So how do you get the Scroll Lock functioning again? Well first let’s run this command
You should get an output like this
xmodmap: up to 3 keys per modifier, (keycodes in parentheses):
shift Shift_L (0×32), Shift_R (0x3e)
lock Caps_Lock (0×42)
control Control_L (0×25), Control_R (0x6d)
mod1 Alt_L (0×40), Alt_L (0x7d), Meta_L (0x9c)
mod2 Num_Lock (0x4d)
mod4 Super_L (0x7f), Hyper_L (0×80)
mod5 Mode_switch (0x5d), ISO_Level3_Shift (0x7c)
Notice mod3 has nothing listed. This will be what we will use to assign Scroll Lock. It may be a different mod for some people. Either way use the one that has nothing listed.
Before we do anything else let’s test this to make sure it works. We’re going to run this command
xmodmap -e ‘add mod3 = Scroll_Lock’
Replace mod3 with whatever the blank mod listing was. Your Scroll Lock should work now.
I hate making changes like this locally to only my user, so I’m going to do this globally.
Now we need to create a file in /etc/X11 called Xmodmap. So start up Gedit or your favorite text editor
gksudo gedit /etc/X11/Xmodmap
Now add this to the file
add mod3 = Scroll_Lock
again, change mod3 to the one that was empty from the first command. Now the Scroll Lock key should get set when X starts now.