I have an ASUS monitor connected to channel HDMI1 from my Lenovo workstation, which is blank (black) all the time.
If I switch it off and on again, it’ll start, show the ASUS animation and then “no signal”, before going blank again.
It used to work fine until a few days ago when I tried to use from a laptop. The monitor works when connected to my raspberry pi, but not to my laptop or my workstation.
I have used different cables, which seem to all work fine with other monitors.
It doens’t appear in Display dialog (I’m using XFCE).
So, this is a weird one, as I have an ASUS (VG248QE) monitor too, and have had a couple of janky incidents with it that involved it not detecting input. Here’s what I did to fix mine.
Unplug the power from the monitor, and then repeatedly press the power button to purge any residual capacitance. Once the light on the power switch no longer turns on, plug the monitor back in.
If needed, cycle through the inputs.
Beyond that, are you seeing input when you post to BIOS?
@Canoe is suggesting a means to fully dissipate any residual power that might be held within the monitor. Alternatively, you could unplug it from power and leave it for a while.
“Post” is what the initial stages of a computers startup process is called. It’s where one might typically jump in and configure the BIOS/UEFI if they needed. If a system fails to post, it’s usually indicator that an issue is hardware related (or at least, not the OS). On your system, I would expect you’d see some “Lenovo” branding at the Post step.
Unfortunately, this site isn’t loading for me at the moment (it’s throwing an error). Could you paste these details into a reply?
Could you also please share the exact model number of your monitor. HDMI leads and monitors have different standards and requirements. A lead working on one, doesn’t precisely mean it’ll work on another. It may not meet the requirements of that monitor.
The monitor has been unplugged for a few days now, that should be fine.
Nothing seems posted to the monitor. I have tried connecting it to other machines and starting this machine (where eOS is installed) from an live USB, but the result is always the same: when starting the monitor, the splash shows ASUS and HDMI, and after a few seconds, it says “HDMI NO SIGNAL”. See here: https://i.imgur.com/rwBLRCU.mp4
I have also tried different cables that work with other monitors, both from DP and USB-C and HDMI into HDMI.
So I tend to think that the problem is in the monitor. I’m confused because the monitor succeeds to start (otherwise there would be no splash), so there must be hope. It just doesn’t seem to be detected.
As I mentioned at the top, the monitor was working fine for months in this machine. The problem started after I tried to use it in a laptop which doesn’t have enough output ports so I had to use some old hub cables which I believe screwed something (another monitor died and this one stopped working).
I have also gone thorugh all menus in EUFI in the hope of finding something related, but no luck.