[solved] "Input Signal Not Found" on second monitor

[F_S_]

Hello,

I have a problem with my laptop: I am using a second monitor through an HDMI cable, which worked properly until yesterday. Today, when I turned the laptop on, it didn't work anymore.

The monitor is an HP Z24 and it just shows "Input Signal Not Found. Check the video cable and video source", but it still works properly if I plug it with the same HDMI cable to another laptop I have.

I already installed the latest system and driver updates and tried disconnecting all the cables and following the procedure described here: https://h30434.www3.hp.com/t5/Notebook-Operating-System-and-Recovery/Input-signal-not-found/td-p/628... but nothing seems to work.

What can I do?

[F_S_]

I called the HP support and the problem was solved.

If it can be useful for anybody: I only had to unplug all the cables and keep the power button pressed for 30 seconds (not only 10, it didn't work!), then restart it normally. Once it was on, I connected the HDMI cable and it was working again.