Screen goes black and have to power off

[jhaines]

Hi,

I am new to kubuntu and have install 16.04 on a desktop that has gone well but having an issue that when the screen sleeps and goes black I cant wake, the only thing I can do is press the power button on the desktop and reboot.

What is causing this? do I need to install a different driver?

Thanks
Julian

[otisklt]

Its a kernel issue from what I can tell, I have a similar problem with sleep of the monitors. In my case it breaks my multi-monitor setup and reduces it to 1 monitor and then does not work properly at all in trying to click on things so I am stuck rebooting.
Separately if I put the whole system to sleep via suspend, it will come back up but the network connection will not. I am stuck rebooting. So I don't use sleep for either case. You can turn off the monitor sleep settings in the power management settings.
Someone else may have another suggestion but I stopped trying to figure out the issue based on a similar experience with Manjaro.

When I boot into Manjaro using kernel 4.14 LTS everything works fine. Monitors go to sleep and wake up with no issues and the system can suspend and come back up with no problems. If I use any newer kernel they offer 4.15, 4.17. 4.18 they all give the same problems with sleep/suspend functionality.

However as a side note on the system suspend I may not have a large enough swap size for Kubuntu 18.04 which is using kernel 4.15 while running with a BTRFS setup based on some things I have read here but I do not set mine the same way as others on there seem to do their BTRFS.
On a 256GB SSD I did a 1GB EXT2 boot partition, a 50GB BTRFS root partition, a 200GB BTRFS home partition, and then a 5GB swap partition. The suggested swap size is the amount of RAM you have + 5%. I have 16GB of RAM so I did not do that in this case.
I guess it comes down to I am not taking full advantage of all the features in BTRFS with this setup but I am ok with that.