I have a Ryzen system powered by a GTX 1050 which originally used a triple-monitor setup comprised of two HP 23" 1080p monitors and a 20" 1600x900 Samsung monitor. I used this configuration on both Windows 10 and 18.04 with no issues (using proprietary drivers).
Recently, I needed my Samsung monitor for a separate setup, and detached it from the PC in question. The setup then was comprised of the two HP monitors, one driven via HDMI, the other DP. With this setup, Windows had no issues. However, Ubuntu continually experienced randomly occurring "black screens", wherein one or both monitors would loose signal and turn completely black for less than 2 seconds with no apparent disruption to any other system functions. The displays always recover from their apparent signal loss, and any playing video or audio seem uninterrupted.
Out of curiosity, I reattached the Samsung monitor (DVI) , and the issue was no longer present. I know that is is probably not enough information to solve the problem, but I'm at a loss as to what I should do to at least diagnose what the issue actually is.
- Ryzen 5 2400g
- Gigabyte GTX 1050 oc
- Asus B350M-A
- HP 2311xi/Z23I, Samsung SA300
Update; Here is the output from xrandr with all 3 monitors attached:
Screen 0: minimum 8 x 8, current 5440 x 1080, maximum 32767 x 32767 DVI-D-0 connected 1600x900+3840+0 (normal left inverted right x axis y axis) 443mm x 249mm 1600x900 60.00*+ 1440x900 74.98 59.89
1280x800 74.93 59.81
1280x720 60.00 50.00
1024x768 75.03 70.07 60.00
800x600 75.00 72.19 60.32 56.25
640x480 75.00 72.81 59.94
HDMI-0 disconnected (normal left inverted right x axis y axis) DP-0 connected primary 1920x1080+1920+0 (normal left inverted right x axis y axis) 509mm x 286mm 1920x1080 60.00*+ 1680x1050 59.95
DP-1 disconnected (normal left inverted right x axis y axis) HDMI-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm 1920x1080 60.00*+ 59.94 50.00
1280x720 60.00 59.94 50.00
640x480 59.94 59.93
Update_2; The random black screens do indeed occur when the Samsung monitor is attached with only one of either of the HP monitors (although seemingly much less frequently, so far I've only noticed it once or twice per uptime within minutes of each boot), however the problem does not persist when only one of the three monitors are connected individually. Also, My system is running the "Tested" 390 driver provided through the Software & Updates app: