The issue seems to be a compatible issue between your new operating system and the hardware of your computer. Please update all the drivers of you computer using Lenovo support website. Use the link below.
I suggest you to run “Run diagnostic” option, It will search issues with the software and hardware.
thanks for your reply. I did run the "Run diagnostics" option and it finished without any issues. All drivers are up to date and hardware is working fine. There is currently no BIOS update available.
I have another thought: Since Windows 7 there is an option available called Hybrid-Standby. I disabled that and rebooted Windows and the blackscreen appeared again, but at the moment Sleep mode is working!
When I run the command "powercfg -energy" I found one suspicios entry, that PCI Express-ASPM (Active-State Power Management) has been disabled due to a known incompatibility to computer hardware. Is there a possible link with my current problem?