Arch Linux

rdw

Member

Registered: 2012-07-02

Posts: 16

Certain keys temporarily do not respond in X/xmonad

I have a Dell Latitude E6230 (laptop) which I have been using Arch Linux continuously on for about 14-15 years. Over the past few weeks (a couple of months at most), certain keys often do not respond initially on the built-in laptop keyboard, particularly when the Shift key is used in conjunction. After pressing some other keys, or some other random keyboard actions, they work again shortly afterwards. I am using a Norwegian keyboard, and it is the keys ?, p, ø, _, * (towards the right hand side) that are particularly affected, and I think some others in the neighbourhood of these. I use xmonad as my window manager. The issue occurs in a terminal, vim, web browser, etc.

I have checked the following:

• Tried in a different terminal with xev at the same time as the issue occurs. Everything seems fine.

• Tried in a different virtual terminal (Ctrl + Alt + F2) at the same time as the issue occurs. Everything seems fine.

My config is as follows. x-monad.hs:

import XMonad

main :: IO()
main = xmonad $ def
    { modMask = mod4Mask
    }

.xinitrc:

#Multimedia keys
xbindkeys

#Set monitor resolution
#xrandr --output DP2 --mode 2560x1440

#Set the mouse cursor
xsetroot -cursor_name left_ptr

#Read the X resources file. 
[[ -f ~/.Xresources ]] && xrdb -merge ~/.Xresources

#Start xmonad
exec xmonad

I tried disabling xbindkeys, and it didn't seem to change anything.

Output of localectl status:

System Locale: LANG=en_GB.UTF-8
    VC Keymap: no
   X11 Layout: no

Output of `setxkbmap -query -verbose 10`:

locale is C
Trying to load rules file ./rules/evdev...
Trying to load rules file /usr/share/X11/xkb/rules/evdev...
Success.
Applied rules from evdev:
rules:      evdev
model:      pc105
layout:     no
Trying to build keymap using the following components:
keycodes:   evdev+aliases(qwerty)
types:      complete
compat:     complete
symbols:    pc+no+inet(evdev)
geometry:   pc(pc105)
rules:      evdev
model:      pc105
layout:     no

Any ideas on how to debug? Is it possible that it is a hardware failure given that xev, etc, seems to work correctly?

rdw

Member

Registered: 2012-07-02

Posts: 16

Re: Certain keys temporarily do not respond in X/xmonad

Actually I think I was mis-reading the output of xev, in fact it seems like a hardware failure (only the Shift key is showing up). Apologies!

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 74,649

Re: Certain keys temporarily do not respond in X/xmonad

Can you post the xev output?

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rdw

Member

Registered: 2012-07-02

Posts: 16

Re: Certain keys temporarily do not respond in X/xmonad

Here is an example where I attempted to press Shift + - to obtain an underscore:

KeyPress event, serial 32, synthetic NO, window 0x1c00001,
    root 0x214, subw 0x0, time 162245172, (216,64), root:(900,65),
    state 0x0, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

KeyRelease event, serial 32, synthetic NO, window 0x1c00001,
    root 0x214, subw 0x0, time 162245481, (216,64), root:(900,65),
    state 0x1, keycode 50 (keysym 0xffe1, Shift_L), same_screen YES,
    XLookupString gives 0 bytes: 
    XFilterEvent returns: False

When the underscore is working, an actual "_" occurs in XLookupString.

It may be a coincidence, but the failures seem to be likely to occur when the CPU is working hard (fan active?), which happens a lot with this old laptop; they do not seem to occur when the laptop is 'calm'. But this is not rigorous, it might be a red herring.

Last edited by rdw (2026-04-17 13:11:09)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 74,649

Re: Certain keys temporarily do not respond in X/xmonad

No signs of any grab - do you have some external keyboard you could try?
The temperature might cause distension, the keyboard bends and the signal gaps

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

rdw

Member

Registered: 2012-07-02

Posts: 16

Re: Certain keys temporarily do not respond in X/xmonad

Indeed, thank you!