My problem is similar to System freeze after suspend, however, it is different enough in my opinion to warrant a separate question. None of the solutions offered there seem to work in my case.
Every time my computer awakes from suspend, it works well for about 5 seconds and then freezes: the mouse pointer is not moving, the text cursor stops blinking, Caps Lock LED does not change, etc... No response to any input, and only hard reset works.
This happened on various previous versions of Ubuntu, ever since I switched from Windows to Ubuntu, about a year ago. And about a week ago, I made a fresh installation of Kubuntu 18.10 (which I love), but the problem remains, so it is probably related to the default settings and my specific hardware. This is happening on my old HP ProBook 4540s.
It happens every time I lift the laptop lid, if previously I closed it while the computer was running.
It also happens if I click on suspend without closing the lid, so I've narrowed it down to awaking from suspend, not just closing and opening of the lid.
As a temporary fix, I've tried completely turning off suspend when the lid is closed, by going to
System Settings ->
Power Management ->
Energy Saving ->
When laptop lid closed and setting it to
Shut down, instead of
Suspend. But this does not work as I would expect: instead of shutting, it first suspends the computer when the lid is closed, then when the lid is opened, it awakes from suspend and then immediately begins to shut down, only to freeze half way in the process.
One of the solutions in the above mentioned question was regarding Nvidia drivers, but my laptop uses Intel graphics, not Nvidia, so that solution does not seem applicable to my problem. I've also tried changing
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to
/etc/default/grub which was also one of the suggested fixes but, just as I suspected, that didn't do much, except change how much text is displayed when the computer boots.
Please, work with me to solve this issue, let me know in a comment what other information is necessary to provide an answer, and I will edit this question.