Reboot and immediately start tapping F2 to open BIOS setup. When it opens, find the USB Wake Support option and make sure it's enabled (see page 65). Don't change anything else in BIOS setup, but save the change to USB Wake Support, if made, and exit setup. When PC reboots, open Device Manager and expand list under Mice and pointing devices. Double-click the entry for the mouse and click its Power Management tab. Make sure the box "Allow this device to wake..." is checked. If that doesn't help, go back into Device Manager and expand list under Human Interface Devices. For all HID that have a Power Management tab, uncheck the box "Allow PC to turn off..." and check the box "Allow this device to wake..." Note: not every device will have both of those options available. Then repeat the same two things for all entries under USB in Device Manager. Note: not every device will have both of those options available.  Then reboot...    
Hello, I have a new Inspiron AIO 5400, BIOS Version 1.2.2, Windows 10 20H2. All Recommended Windows updates have been installed and all drivers have been updated from Dell SupportAssist. When i don't use the pc for a certain period of time the display turns off automatically;  but  later on, moving the mouse or press any key on the keyboard, the PC doesn't wake up and the screen remain black. The PC doesn't enter sleep mode because led remain on and i can hear fan noise. I tried to change times on power settings (Balanced and Dell Power Plan) and to create a customize power plan but didn't fix the problem. Has anybody had this issue before? Recommended solutions? Thanks
AIO 5400 SLEEP MODE