Carefully check the messages around going to sleep and when trying to wakeup whats going on there.

There have been suggestions that it is a kernel bug, also a plot between Microsoft and the BIOS makers. My money is on the kernel bug, or some oversight in the installation scripting.

Well if it is then upgrade your kernel you are four versions behind, the -31 kernel just came out yesterday. For the sleep problem no clue I never use it.

From the web, this seems a common problem across many distros, with numerous "solutions" which work for some but not others. "Solutions" have included increasing the swap file size, keeping USB ports open to signals, and waggling the mouse around. Frustratingly, the problem is often declared "Solved" and a thread closed when it is only solved for the one OP user, or when someone points to a "solution" given years ago.

When I try to wake by pressing a key or the power button, the system unit fans restart but the monitor screen stays black and its indicating lights show no signal being received. As an experiment I have sent it to sleep with a terminal session open, "woken" it by pressing a key, and then blindly typed in a command to make an audible beep - and get no beep. I can only do a full power off and restart.

Maybe related, when I go to a full screen text session (Ctrl-Alt-F1) and then return to GUI session (Ctrl-Alt-F7), I am placed at the GUI log-in screen and find nothing has been saved.

Things that don't work for me, some being those suggested solutions :

• Trying to wake by pressing a key, waggling the mouse, pressing the power button, or pressing the reboot button

  Trying to wake after sending to sleep by the menu in the GUI

  Trying to wake after installing pm-utils and sending to sleep with "pm-suspend" from a su command line

  Ensuring swap partition/file is larger than RAM (surely this would only affect Hybernate and not Sleep?)

  Not sharing the swap partition/file with another distro

  Ensuring  swap partition in fstab has same UUID as in cfdisk as "Filesystem UUID"

  Ensuring /etc/initramfs-tools/conf.d/resume file points to same UUID as swap in fsstab
    .. followed by update-initramfs -u and reboot

  Fresh install of Daedalus on a dedicated drive with three partitions - root, home and unshared swap. (My data is on another drive)

There have been suggestions that it is a kernel bug, also a plot between Microsoft and the BIOS makers. My money is on the kernel bug, or some oversight in the installation scripting.

Anyway, I 'm not prepared to work without the sleep mode so I wiped that Daedalus drive and intalled Chimaera, image 5.10.0-9-amd64, in the same way, adding pm-utils. Sleep from "pm-suspend" and waking with the power button works in Chimaera.

Any better ideas, or future bug fix, would be welcome.