I have a dual boot Lubuntu 21.10 / Windows laptop. Recently it won't suspend (sleep). No matter I do it from start menu or use command line
systemctl suspend . After trying to suspend, laptop's fan turns on with high speed, maybe trying to cool the CPU. Anyway, latop won't enter suspend even after 15 minutes. Neither, power led goes blinking or fan stops.
Saw logs by command
sudo journalctl -b -1 -e but nothing special I found.
I checked many other question like this but no success.
Also I added
/etc/default/grub but the only difference was that fan speed did not go high speed.
Consider that Windows suspend correctly. Even the Lubuntu was sleeping correctly few months ago.
I am trying a couple of work-arounds to resolve this issue:
I upgraded to version 21.10 but nothing changed.. It was 21.04 when I started to see this issue. When I try to suspend my laptop manually or by the command
systemctl suspend, just the screen turns off. Fan and power LED are still turned on even after 5 minutes. Also laptop won't turn on by pressing keys or touching mouse, only a forced shutdown by pressing the power button for some seconds forces a shutdown.
Tried Windows to make sure. It suspends correctly: fan is turned off and power LED goes blinking. Also tried both Windows shutdown and restart. Same problem exists.
Was suspect about network card, so turned it off by
nmcli radio wifi off, fail again.
Checked suspend logs with command
journalctl | grep systemd-sleep and found "BIOS may not properly restore RDRAND after suspend". My Laptop is on AMD CPU. Then searched and found a solution and applied it as:
sudo featherpad /etc/default/grub
but stil failing.
I can see that the shutdown does not work as well. When I shut down, laptop fan goes high speed, screen is black and power led still is on.
Update 7 Feb. 2022
Shutdown and suspend returned to my laptop automatically. From my last activity on this issue I just did 1 or 2 regular updates of the OS and nothing else. And the problem is solved now. I do not know why.