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?
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.