[SOLVED] Second monitor recognizes laptop input, then sleeps

[a.a.46]

I have a second monitor I use to extend the desktop on my laptop. It previously worked fine, but now it recognizes the laptop's input and sleeps after displaying the extended top for a second or two. I have tried unplugging the monitor, checking cable connections, and restarting the laptop.
Laptop is a Dell Precision 5520 running Windows 10 and the monitor is an Asus VE205. They are connected via an HDMI to VGA cable. Thanks for any help!

 

[Phillip Corcoran]

Top suspect at this stage has to be that HDMi-VGA adapter cable --- so I would start by replacing that --- make sure you buy an active one though, and don't buy the cheapest.