Ok i "may" have solved the mystery. Atleast on my machine. Will keep a close eye on this for next couple of days to see if this is a permanent fix. Here is what i want you to do so please let us know if this worked for you:
1. Rightclick on empty taskbar area or clock on taskbar (if taskbar full) and select "Start Task Manager".
2. Check under Processes tab if the following processes are running:
3. If YES then likely your blackscreen issue might be of different nature but keep reading anyway. If NO then keep reading:
4. Press Windows Key & R. Type in services.msc
5. In the opened window doubleclick "AMD External Events Utility". Should be 3rd on the list or very near the top.
6. Change Startup type to Automatic and press Start. Click ok to close the dialog and X to close the window.
7. Check back into Task Manager if the 2 processes mentioned above are now running. If YES then change monitor timeout to 1 minute and test 3 times to see if monitor wakes on each of those times with both keyboard and mouse presses.
8. If NO or you got an error message when trying to start the mentioned service then you need to reinstall catalyst drivers. This service is installed regardless of CCC so installing or not installing CCC does not matter.
Working Theory: By description this service seems to have something to do with CCC and keyboard shortcuts but thats clearly not the full extent of its functions. Wich could explain the fact that when you have this disabled or not running then keypresses are not correctly registered during monitor timeout (when ZeroCore is active?) and thus a more substandial display refresh is required to wake the monitor (CTRL+ALT+DEL). I also noticed my display quickly blinked when i enabled this service so it defenetly has more to do with the display then the description would suggest.
Then i disabled this again and sure enough when i tried to wake the display with a mause it woke up correctly but when i tried to wake with a keyboard i got a black screen and even moving the mouse didnt help at this point.