Trouble resuming / cold starting with monitor off

Hi, on a desktop with Fedora 40. If I forget to turn my monitor on prior to resuming after suspend or cold booting, I seem to get stuck on a blank screen (monitor says ‘no input’ even after taping keys, clicking the mouse and waiting …). Can recover by rebooting again with the monitor on, but wondering is there a better way to deal with this?

Just out of curiosity.
Most modern monitors have a ‘standby’ feature where the monitor itself sleeps after a short time with no signal. It then powers off the backlight and screen but remains waiting for a signal from the PC to wake up. Does yours not have that feature?

If it has a standby feature then there really is no gain in powering off the monitor but let it sleep instead and the desktop will see it already powered on when starting up from suspend.

When doing a cold start make a habit of powering on the monitor first, or leave it in standby as well.

Thanks yes I think my monitor has a standby feature.
Without checking the documentation my naive assumption is that the standby monitor uses a small amount of energy to offer a wake time that is faster than a cold start - is that not the case?
Checking the monitor is powered on first works 100% of the time I remember to do it :wink:

As with all electronics that have a standby feature, yes there is a tiny power demand while sleeping. It is your choice to use that feature or not. The PC also has a constant power demand when suspended which would be much more than the power draw for the monitor in standby.

Apparently without using the standby and shutting the power off to the monitor it is inconvenient if you fail to remember and power it back on before starting the PC.

Very true re the PC power draw. (I think the teenage eco police that monitor my behaviour give this a pass on account of the shiny RGB :)).
I might go old school for the moment and put a post-it note near the keyboard.
Thanks again

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I have seen this with amdgpu on a cold start.
But have not investigated beyond noticing.

I can turn on and off the monitor after booting without issue.

Yes, turning the monitor on and off after booting is not an issue and it is in fact an AMD GPU.
It’s resuming or cold booting with the monitor off that causes an issue.

Added amdgpu