My computer was working fine. Until the monitor just wouldn’t come on any more. It was old, had a vertical blue pixel line, and it was time to order a new one. In the mean time, I had an old monitor, but it only had a VGA and DVI port. My computer only has an integrated HDMI and Display Port. So I got an HDMI to DVI adapter which is supposed to work both directions.
When it boots with this temporary monitor, it shows the grub2 menu, but at a low resolution. If hitting enter, or waiting the 7 seconds, the screen goes blank, but you can hear the operating system loading. If I put “nomodeset” on the “linux” grub line, it will load into low resolution desktop. I think it was something like 640x360 when I checked. If I then reboot, it will then load into 1920x1080 desktop.
I tried a number of other things, which I don’t remember exactly, but none worked. Some such as grub_gfxmode=1920x1080x32, and plymouth.enable=0. The plymouth was the last I tried, and it was a blank screen. I have the power button to pop up the logout screen. By operating blindly, I then press the left arrow twice to the reboot, press enter, and the system reboots. It comes up, shows no grub menu nor any other thing, then after about 7 seconds, it loads into proper desktop at 1920x1080.
It’s like it’s not sensing the proper video settings, and showing the screen into never-never land. But after rebooting, it senses the right video, but then grub has problems displaying. Do you think it’s the HDMI to DVI adapter causing issues? I’m a little concerned that the new monitor may have trouble. However, my old HDMI monitor did work fine and the new one has an HDMI port. But I’d like to understand what’s going on for any future situations.
When displaying correctly:
>sudo lspci -nnk | grep -A3 VGA
[sudo] password for root:
07:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] [1002:1638] (rev c9)
Subsystem: ASUSTeK Computer Inc. Device [1043:8809]
Kernel driver in use: amdgpu
Kernel modules: amdgpu
Something which may not be relevant, is when originally upgrading my computer system some time ago, I had no monitor display of anything. Only until I took out the CMOS battery and held the power button down for awhile, did it start working okay. But I’m guessing the BIOS may have been set to an external graphics card for factory testing.