If your second monitor goes to sleep on your Windows computer and doesn't wake up, you can follow these tips to get rid of this problem.

Oftentimes the PC and the other monitor are in Sleep mode, but the backlight on the PG279Q is still on; it's quite visible as it's IPS.

Disable Deep Sleep on Monitors Some monitors, especially Dell monitors, have a feature called Deep Sleep, which lowers the power usage of your monitor even more than going into regular standby mode.

This is a really stupid question, but why can't I stop my monitor from going into "standby" mode? I've messed around with the screensaver settings and the "energy saving features of monitor" and ...

If Windows cannot detect the second monitor after waking up from Sleep mode, then here some working solutions to help you fix the issue.