I have an older desktop PC that has been running Ubuntu Gnome perfectly for the past 18 months until last week. The last hardware change to the machine was addition of Blutooth via USB about 3 weeks ago.
Starting a few days ago I would leave the machine for some time, half hour or so. When I returned the monitors would come out of sleep and I can move the mouse but both monitors are black.
Today I rebuilt the machine. Same /home directory but formated the system disk and did a fresh install. Unfortunately the problem persists.
I'm not sure if I should threat this as a hardware of software issue and am hoping to get advice for solution or debugging.
System is Dell XPS 8100, 10 years old, i5, 16GB RAM, 500 SSD system disk with /home on 250 SSD. Don't remember what my graphics card is but pretty generic $40 card I purchased 3 or 4 months ago. Ubuntu Gnome 16.04.2 with all updates applied.
Power settings
Blank screen 5 minutes Wi-Fi off Mobile broadband off Automatic suspend off
EDIT Graphics card is
01:00.0 VGA compatible controller: NVIDIA Corporation GT218 [GeForce 8400 GS Rev. 3] (rev a2)
Thanks
lspci
to find out, as it is the most likely culprit, not the card itself but eventually a wrong or missing driver. Please [edit] and add that info. – Jul 25 '17 at 00:10