I’m just chiming in to report a similar issue, which seems to be caused by the nVidia proprietary driver on Linux.
SUMMARY
If I turn off my TV (being used as a monitor) for longer than maybe 15 mins, then when I turn it on again, I just get “no signal”. Seems to happen at least 90% of the time.
I get a similar issue when attempting to resume from Sleep.
STEPS TO REPRODUCE
- Turn off TV using the remote. Or use the “turn off screen” setting in Power Management.
- After >15 mins, turn on TV again.
OBSERVED RESULT
TV stays at “no signal”. Using keyboard/mouse has no effect. I have to do a hard power off on my PC by holding down the power button.
EXPECTED RESULT
TV should display the desktop (or lock screen) as usual.
SOFTWARE/OS VERSIONS
Operating System: Kubuntu 24.10
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.6.2
KERNEL: 6.11.0-9-generic
CPU: Intel Core i5-14600KF
GPU: NVIDIA GeForce RTX 4070 Ti SUPER
GPU DRIVER: NVIDIA 560.35.03
RAM: 32 GB
Display: LG C3 4K 42" OLED TV, connected via HDMI
WORKAROUND
Switch to the nouveau open-source driver. However this is limited to 60Hz, has no HDR and generally looks less good.
Alternatively, use the nVidia driver, but in Power Management settings I prevent the display from turning off. I also don’t use sleep at all. Instead I configure my PC to turn off (shutdown) after 15 minutes of idle time.
ADDITIONAL INFO
- I don’t get this issue on Windows 11 with the same hardware. Sleep also works correctly in Windows.