Has it always done this or something new? Might be your Power plan settings: Reboot PC and open Device Manager. Expand list under USB. Double-click each USB entry and click its Power Management tab, if it has one. Uncheck the box "Allow PC to turn off...". Repeat for all USB entries.Now expand list under Human Interface Devices in Device Manager and uncheck that same box for any HID entry that has a Power Management tab. Exit Device Manager when done.Next, open the Windows Power & Sleep screen. Click Additional Power Settings. On next screen identify the active Power plan and click Change Plan Settings. On next screen, click Change Advanced Power Settings.On that last screen, disable Hibernation, Hybrid Sleep, USB Selective Suspend, and PCI Express Link State Management. Save the changes to the Power plan and reboot. Does that help?
During the day, if I walk away from my computer for an hour or so, when I come back the screen is black, and the computer it totally unresponsive, i.e., tapping a key or moving the mouse doesn’t get it back up and operating again.  The power button is still on/lit, and the hard drive light will occasionally blink, which leads me to believe that the computer is doing something, but I have no idea what.  I have the sleep mode set to NEVER in Settings.  The only way I can get the computer back up and running it to hold the power button in for about 10 seconds until the computer shuts down, wait a minute, and restart it.  Then it works fine again.  Why is it doing this???  I have all the Windows updates installed, and I run Dell Support Assist monthly to be sure everything is up to date. P.S. One night after watching TV, I checked the computer, and it was blank as described above, i.e., totally unresponsive.  I let it alone and went to bed.  The next morning, I moved the mouse and the computer was up and running.  What was it doing that it wouldn't let me use it?
Sudden black or blank screen on Inspiron 3880 Windows 10