Question Why is my second monitor black but screenshots works fine?

[Sproo]

My monitor stopped working one day. It works for a few seconds when i turn it off and then on but then goes back to black. What I've noticed is that when i screenshot it actually shows my monitor. Is the display broken or might it be my gpu? Have in mind that my monitor is pretty old, around 15 years.

EDIT: It's not being detected by windows.

 

[Ralston18]

Update your post to include full system hardware specs and OS.

Include monitors: make and model.

Have you tried another known working video cable between your pc and problem monitor?

What happens if you physically switch the monitors?

Have you tried the problem monitor on another known working PC (not the current host)?

Have you tried another known working monitor (#3) from another computer?

Key is to determine if the problem follows the monitor or stays with the current host computer.

All in all, a 15 old monitor may have hit its' EOL (End of Life).