Unfortunately, there is no universal cause for this, so there’s no universal solution. However, seeing as there are several possible ways to resolve this, I’m going to run through some of the most popular causes and solutions to this age-old issue.

Disable Deep Sleep (Dell Monitors)

Dell monitors (and maybe others) have a special feature called Deep Sleep, which lowers the power usage of your monitor even more than going into regular standby mode. It’s somewhere between outright unplugging in your monitor and just having it in standby. In most cases, it’s not a very useful feature and can mean that if your monitor goes to sleep with your PC, then your monitor won’t automatically turn on again when your PC comes out of sleep. This means you have to manually turn on your monitor when Deep Sleep is enabled. You can do that or just disable Deep Sleep on the monitor. To do this, turn on the On-Screen Display on your monitor, select “Others -> Monitor Deep Sleep,” then disable it there. Note that other monitor brands might also have this feature, so take a look in your monitor settings to see if you have it, then disable it if you like.

Disable PLL Overvoltage (ASUS Motherboards)

Asus deals with a lot of motherboards, and for the most part, they deal with them quite well, but there are a couple of quirks on them that can cause things to go a little bit wrong. For example, most modern-ish Asus boards have a feature called “PLL Overvoltage” enabled by default. This helps overclock your CPU that little bit more, so if you’re worried about eking out those extra few-hundred MHz out of your rig, you may want to leave it on. But if getting your PC some sleep is a priority, then you may need to turn this feature off, and to do that, you need to go into the dreaded BIOS. Reboot your PC, then as it’s booting, press the Delete key until the BIOS screen appears. Things may vary a bit here from one motherboard to another, but to find the option, go into the “Advanced Mode” (the F7 key on my Asus Z97 MOBO). Next, select “AI Tweaker” from the options at the top of the screen, then click the drop-down next to “Internal PLL Overvoltage” and change it to OFF. Save the settings and exit the BIOS.

Sometimes those seemingly helpful power options in Windows can prove to be a liability, accidentally keeping certain things in a dormant state, even when they’re definitely meant to be on. Here’s how to make sure power management doesn’t interfere with your monitor. Go to “Control Panel -> Power Options,” then select “Change plan settings,” for the power plan you’re currently using, and “Change advanced power settings.” Next, scroll down to “PCI Express,” click the “+” icon next to it, and under “Link State Power Management,” change the setting to “Off” and click “Save changes.”

Disable Auto-Detect in Monitor Settings

A seemingly simple option but a good one. When your monitor goes to sleep, the connection between it and the cable connecting it is severed. For some silly reason, however, when the connection gets re-established (when you bring your monitor out of Sleep mode), sometimes the monitor doesn’t re-establish that connection, even though the cable is still plugged in. A possible solution to this is to use the buttons on your monitor to switch off the “auto-detect” option. One of these solutions should solve your woes with reawakening your monitor. While you’re working with Windows, see our list of Windows 10 registry hacks. Also see how to install unsigned drivers in Windows 10.