I'm not sure if this is the card or the monitor doing this.
Card: MSI Radeon RX 480 Gaming 4G
Driver: 18.6.1 (as well as previous)
Monitor: LG 43UD79-B
Okay, I noticed once before when I switched the monitor off, that I would get no signal when switching it back on. but I wasn't sure if that was a one-off thing.
Then recently I built an ITX rig in my Corsair 380T, and had been running split screen 1920x2160 with both it and my main rig side by side on the screen.
When switching back to 3840x2160 on my main rig with the RX 480, it goes to no signal. I also noticed this can happen in reverse when going into split screen as well.
Is this the card, driver, or monitor?
The only cure I have found is to press the power button on my main rig for an orderly shutdown, or when that hangs, the full five second forced power off. Apparently, CTRL-ALT-DEL->DOWN->DOWN->ENTER to log out doesn't reset the driver, and things still remain no signal.