I am having the same issue. I first tried with Ubuntu Gnome 16.04 and then with Ubuntu 16.04. Both have the same issue. Doing "sudo pm- hibernate" can duplicate the issue. I am attaching a report from lshw. My computer is a HP Pavilion dv7.
** Attachment added: "lshw output for HP Pavilon dv7" https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/1570921/+attachment/4643129/+files/hw -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pm-utils in Ubuntu. https://bugs.launchpad.net/bugs/1570921 Title: suspend not working Status in pm-utils package in Ubuntu: Confirmed Bug description: My computer cannot go to suspend state. The monitor switch off but the cpu/cpu fan keeps running and the hard drive is active. It doesn't respond, I need to switch off manually to reboot the system. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: pm-utils 1.4.1-16 ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6 Uname: Linux 4.4.0-18-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: Unity Date: Fri Apr 15 18:42:49 2016 InstallationDate: Installed on 2016-04-15 (0 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160414) PackageArchitecture: all ProcEnviron: LANGUAGE=hu PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=hu_HU.UTF-8 SHELL=/bin/bash SourcePackage: pm-utils UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/1570921/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp