I have an Acer XV340CKP monitor connected via Display Port to my GPU. I also have a old LG W2253TQ that I use as a secondary display. It only has a DVI and VGA port. I have a DVI-DVI cable together with a DVI-Display Port converter to connect to my GPU, which is an Asus RX6900XT. I am running Nobara 38.
I have observed that if I were to have my Acer monitor powered when I switch on my desktop, all the monitor buttons do not respond. None of the menu buttons, not even the power button responds. When I switch off the desktop, the monitor stays on. The only way to power it down is to unplug the power cable.
However, if I were to only have the LG monitor powered when I switch on my desktop, all the buttons on the Acer monitor works.
I believe everything was working previously in Nobara 37. I think this issue probably started happening in the recent month or two.
Is this even possible, where the graphics card sends a malformed signal to the monitor and prevents the buttons from working?
DVI should not control the monitor's actual physical controls - it does include a small non-display channel but IIRC that's used to get the display modes info from the monitor, and potentially to transmit contrast information and the like; some monitors will prevent you from adjusting contrast if DVI sends that info for example, but it certainly shouldn't disable the power button.
My guess would be a hardware issue - in the monitor itself - which is somehow triggered by the sequence in which you do enable the displays, and your system update being unrelated. It's a huge guess though. One thing to try is repeating both sequences (the one that locks your buttons and the one that doesn't) using a live CD - not a "nobara 38" one if such a thing exists, another distro. Trying both monitors on another computer would be an interesting test as well, although not necessarily that helpful (because if it doesn't occur there, it might just mean the issue is triggered by peculiarities in your graphic card).
So I decided to bite the bullet and did a fresh install of Fedora 39 and that appeared to have made the issue go away. In the process of installing updates and configuring it the way I like, the monitor control buttons on both monitors response. So, it seems like the cause of the issue could have been a glitch during an update. Who knows? At least I know that it's not a hardware issue (cross finders). :)
How old is the Asus monitor? This might also be a hardware problem, bad caps related. Digital equipment is sensitive to power voltage fluctuations, and when bad caps are in the picture, even more so, making the equpment do all sorts of inexplainable things, like how could one thing I do on this monitor reflect on what the other monitor does or doesn't. In most cases, a small ground loop or a fluctuation caused by one of the monitors draining power when being turned on or off, might affect what the other one does or doesn't, if it alredy has failing caps. I've seen similar things happen on dual monitor setups when one of them has failing caps. One turns on just fine the other one doesn't, but you power them in reverse order, hey they work 😂.
Very interesting. The Asus monitor is probably only 2 years old. It does work fine standalone with a spare laptop of mine that is running Windows 10 though.
Have you tried to replicate this behavior in Windows? Try it with a spare drive, see if you get the same irrational thing happening in Windows. If it happens, yeah, it's a hardware problem 😉... most probably bad caps. Bad batch maybe, even though it's only 2 years old, who knows.
I did not try replicating this behavior with a Windows install on my desktop. I did however perform a fresh install of Fedora 39 and that appeared to have fixed the issue, which is good news.
Well, it's not a hardware problem in that case 😉. Good thing you fixed it 👍.
My brother had a screen that would occasionally reboot with fullscreen video, but not if you kept some window decoration onscreen. There must've been some degree of (you can not turn it off) image processing that would shit itself. Maybe it was local dimming related.
Everything is filled with software, and a lot of it is hot garbage.
