How to Fix a Second Monitor Windows Does Not See After Sleep

The second monitor is powered on and showing its logo or "No signal," but Windows acts like it was never plugged in. The monitor went into a deep power-saving state during sleep and Windows dropped it from the display list instead of waiting for it to wake. Restarting the graphics driver or forcing a rescan brings it back, and one setting in the monitor's menu stops the repeat.

Restart the graphics driver

Press Windows + Ctrl + Shift + B. The screen goes black for a second, the PC beeps, and both displays redraw. Nothing closes, and this alone fixes the problem most of the time.

Set the display mode to Extend again

Press Windows + P and choose Extend. Windows sometimes falls back to PC screen only when a monitor disappears, and picking Extend again forces it to look for the second display.

Click Detect

Go to Settings, System, Display. Expand Multiple displays and click Detect. If the monitor appears in the layout diagram, drag it into position and click Apply.

Power-cycle the monitor and reseat the cable

Turn the monitor off at its power button, wait ten seconds, and turn it back on. If it still shows nothing, unplug the video cable at both ends and plug it back in. DisplayPort is the usual offender: a DisplayPort monitor reports itself as unplugged when it sleeps, and some graphics drivers take that literally.

Turn off the monitor's deep sleep option

Open the monitor's own on-screen menu with its buttons. Look for Deep Sleep, DisplayPort Power Saving, DP Power Save, or a similar item under a Power or System section, and turn it off. This is the change that stops the monitor from vanishing every time the PC sleeps.

Update the graphics driver

Open Device Manager, expand Display adapters, right-click the graphics card, and choose Update driver. A driver from the card maker's site is usually newer than what Windows Update offers. While there, expand Monitors, right-click the monitor, choose Properties, and on the Power Management tab untick any option that lets Windows turn the device off.

If the monitor runs through a docking station. Docks have their own firmware, and old firmware is a common cause of displays that never return after sleep. Run the dock maker's update tool.

If the monitor wakes on the wrong input. A monitor that comes back showing HDMI 1 while the PC is on DisplayPort is switching inputs on its own. Turn off auto input select in the monitor's menu, or pick the correct input with its buttons. That is a monitor setting, not a Windows one.