DEL (CANC) key not working

Hi, unfortunately I have found the time to open this thread only now, but it has been a while since my DEL key (the one that in an ISO keyboard is located in the top-right corner, exactly next to F12) has not been working. I am almost sure it is not a mechanical problem.

Is anyone else experiencing this? Do you have any idea on how to troubleshoot/debug this?

Thanks a lot!

             .',;::::;,'.                tommi@tfw 
         .';:cccccccccccc:;,.            --------- 
      .;cccccccccccccccccccccc;.         OS: Fedora Linux 40 (Workstation Edition) x86_64 
    .:cccccccccccccccccccccccccc:.       Host: Laptop 13 (AMD Ryzen 7040Series) A7 
  .;ccccccccccccc;.:dddl:.;ccccccc;.     Kernel: 6.9.8-200.fc40.x86_64 
 .:ccccccccccccc;OWMKOOXMWd;ccccccc:.    Uptime: 19 mins 
.:ccccccccccccc;KMMc;cc;xMMc:ccccccc:.   Packages: 2365 (rpm), 116 (flatpak) 
,cccccccccccccc;MMM.;cc;;WW::cccccccc,   Shell: zsh 5.9 
:cccccccccccccc;MMM.;cccccccccccccccc:   Resolution: 2256x1504 
:ccccccc;oxOOOo;MMM0OOk.;cccccccccccc:   DE: GNOME 46.3.1 
cccccc:0MMKxdd:;MMMkddc.;cccccccccccc;   WM: Mutter 
ccccc:XM0';cccc;MMM.;cccccccccccccccc'   WM Theme: Adwaita 
ccccc;MMo;ccccc;MMW.;ccccccccccccccc;    Theme: Adwaita [GTK2/3] 
ccccc;0MNc.ccc.xMMd:ccccccccccccccc;     Icons: Adwaita [GTK2/3] 
cccccc;dNMWXXXWM0::cccccccccccccc:,      Terminal: kgx 
cccccccc;.:odl:.;cccccccccccccc:,.       CPU: AMD Ryzen 7 7840U w/ Radeon 780M Graphics (16) @ 5.132GHz 
:cccccccccccccccccccccccccccc:'.         GPU: AMD ATI c1:00.0 Phoenix1 
.:cccccccccccccccccccccc:;,..            Memory: 6440MiB / 27858MiB 
  '::cccccccccccccc::;,.

Sorry, I was confused. The DEL key, the one that in an ISO keyboard is located in the top-right corner (exactly next to F12).

1 Like

The Delete key is the most right in the upper right corner and works as expected on Fedora 40. This key is a dual key, basically, and when I press the Fn key, its behaviour changes into an Insert key, which also works fine.

You could try using the libinput to monitor the key events your system receives when you press the keys. In short:

  1. Run sudo libinput list-devices and find which device represents the keyboard. On my system, this was the /dev/input/event2.
  2. Run sudo libinput debug-events /dev/input/event2.
  3. Start pressing the keys and you will see immediately, what signal is received when you press those keys. The Delete key should produce the KEY_DELETE signal.
2 Likes

Thanks so much, @Lukas_Ruzicka!

This is my output after running sudo libinput debug-events /dev/input/event2:

sudo libinput debug-events /dev/input/event2
-event2   DEVICE_ADDED            AT Translated Set 2 keyboard      seat0 default group1  cap:k
 event2   KEYBOARD_KEY            +9.469s	*** (-1) pressed
f event2   KEYBOARD_KEY            +9.536s	*** (-1) released
 event2   KEYBOARD_KEY            +9.982s	*** (-1) pressed
f event2   KEYBOARD_KEY            +10.043s	*** (-1) released
 event2   KEYBOARD_KEY            +10.407s	*** (-1) pressed
f event2   KEYBOARD_KEY            +10.470s	*** (-1) released
 event2   KEYBOARD_KEY            +10.594s	*** (-1) pressed
f event2   KEYBOARD_KEY            +10.700s	*** (-1) released
 event2   KEYBOARD_KEY            +12.350s	*** (-1) pressed
t event2   KEYBOARD_KEY            +12.422s	*** (-1) released
 event2   KEYBOARD_KEY            +12.886s	*** (-1) pressed
e event2   KEYBOARD_KEY            +12.978s	*** (-1) released
 event2   KEYBOARD_KEY            +13.144s	*** (-1) pressed
s event2   KEYBOARD_KEY            +13.228s	*** (-1) released
 event2   KEYBOARD_KEY            +13.379s	*** (-1) pressed
t event2   KEYBOARD_KEY            +13.433s	*** (-1) released
 event2   KEYBOARD_KEY            +18.269s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +18.447s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +18.543s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +18.665s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +18.905s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +19.115s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +19.321s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +19.545s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +19.757s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +19.869s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +20.012s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +20.101s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +20.186s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +20.276s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +20.394s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +20.639s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +20.793s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +20.880s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +20.952s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +21.034s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +21.106s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +21.179s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +21.259s	KEY_DELETE (111) pressed
^[[3~ event2   KEYBOARD_KEY            +21.326s	KEY_DELETE (111) released
 event2   KEYBOARD_KEY            +23.193s	*** (-1) pressed
 event2   KEYBOARD_KEY            +25.166s	*** (-1) pressed

The problem is that I was pressing the KEY_DELETE button even before it appeared, and it got detected only when I started pressing more aggressively. Is there a software explanation for this, or is it a hardware problem?

Hello,
if the Delete key works when pressed more agressively and does not when pressed moderately, I would assume that it is indeed a hardware problem. I have never heard about tactile keys that would change their meaning depending on the pressure.

You can also try an external keyboard and see what signals are sent from that external keyboard. If everything is ok with them, then hardware problems is the most probable cause.

Although … when I take a look at your log file … it is interesting that it does recognize that something is pressed, but it does not say what. The events between +9 and +13 seconds, is it also you pressing the delete key?

1 Like

Nope, they are other keyboard keys.

Hardware is the most probable explanation.

Thanks a lot!

Hi!

Unfortunately, I am really sure the issue is not a hardware problem. Even when I press the DEL key aggressively, sometimes it does not work!

I really can’t understand what could be the problem

Sometimes hardware issues can be intermittent or depend on unknown variables.

It could be a bad contact or broken, but still intermittent touching, wire. Sometimes a keypress will be just right to work, other times it won’t.