[NAME]  Have you ever tried connecting an external monitor to the HDMI-OUT on this PC and see if you get a black screen when waking? Try this....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. See what happens when you wake PC now.  Might not solve black screens at startup, but possibly when waking... Also, look in BIOS setup (reboot and tap F2 at Dell splash screen) and tell us what Primary Display options are listed (don't change them, yet).  Then just exit BIOS setup without changing anything.
Sometimes, after I've started my Dell Inspiron 27 7700 AIO and log in with my 4-digit password, all I get is a black screen.  I can press Ctrl-ALT-Delete and it gives me these options (Lock, Switch User, Sign Out, Task Manager).  After I sign out and back in again, sometimes my desktop screen comes up and sometimes it doesn't (still a black screen).  In the latter instances, I have to completely restart the computer and it usually works.   Also, when my computer has been idle for awhile and goes into sleep mode, when I try to wake it, sometimes it "awakens" to a black screen or it will awaken to the login screen, where I will input my password, and then I get the black screen again. This computer is 2 months old and shouldn't be doing this.  About a month ago, all of a sudden, a rectangular box showed up at the top left side of my screen and wouldn't go away.  The chat agent suggested I restart and it went away then, but the agent couldn't tell me why this happened in the first place.  All these things seem to be happening with my screen.  Is there a known issue with the screen of these AIOs?
Inspiron 7700 AIO, black screen on login