Black screen part way through booting - Power Key needed to recover

I've recently updated an HP EliteBook 8560p from Windows 7 Pro to Windows 10 Pro. Once booted (see below) the display looks good and everything runs fine. However, booting requires the following steps:

1) Press the Power Button. The system seems to start up with the Windows "flag" and the rotating circle of dots showing for a couple of seconds. Then the screen goes black - no cursor or anything but the disk activity light indicates that the system is (apparently) continuing to boot.

2) Wait until the disk activity light stops flickering. The system is NOT sleeping at this point.

3) Press the Power Button to put the system to sleep.

4) Press the Power Button AGAIN to "wake up" the system AND THE SCREEN.

NOTE: This system always seems to require that the Power Button be used to wake it up from sleep. Although configured to allow them to do so, neither the keyboard nor the mouse will wake the system. This limitation may or may not be related to the "boot" problem mentioned above.

I have used Device Manager to update all the drivers. The driver for the AMD Radeon Graphics HD6470M is version 15.201.1301.0 dated 8/19/2015, which I believe is the latest one.

Any thoughts/suggestions would be greatly appreciated!

I probably should have mentioned that this system has been updated with an SSD and Hibernation has been turned OFF, which also appears to turn OFF the fast startup option. I've used the powercfg command to verify that both the keyboard and mouse are configured such that they should be able to 'wake' the system. (Also, using Device Manager => Power Management for those devices I've verified that the check boxes for "Allow this device to wake the computer" are, indeed, checked.)

Apparently there is a newer version, see this" https://www.amd.com/en/support/graph...adeon-hd-6470m

I would try the Crimson driver first. If this doesn't work, use DDU (Display Driver Uninstaller) to remove Crimson, then try the Catalyst driver.

I may give one of these drivers a try, but from reading elsewhere is appears that my currently installed driver (15.201.1301.0 dated 8/19/2015) should work with Win 10. Since the system is quite usable (except for the annoying need to use the Power Button more often than should be necessary) I may just "give up" on resolving the strange behavior mentioned in my original post. I'm still surprised, though, that no one else seems to be having the same problems after updating to Windows 10!

Thanks to everyone who responded, and to anyone who may add comments in the future!

Hello! Thanks for the info on the Windows Performance Recorder (WPR). While trying to run that program I immediately get an error message Hot key is already registered followed by Error in registering keyboard shortcut to save recording. I've searched, but I can't find any info on what "hot keys" are used by the WPR.

Since the problem system is being used on a regular basis it isn't practical to install a different version of Win 10.

I'd like to check out the BIOS in more detail, but unfortunately access is protected by a password which no one knows! I can view the BIOS as "Guest" and see that keyboard and mouse SHOULD be able to wake the system.

If I can get the WPR working it might shed some light on the problem(s)!

Thanks, Wayne