What i heard about this monitor is too sensitive of electricity, any leak electricity from your psu or motherboard will channel to your lenovo and become black screen.
You can use test light or voltage tester and touch it to your casing near PSU if there is any light then we have same problem.
To avoid this your home must have cable grounding in outlet wall that you use for your pc, so any leak electricty will channel/transfer to cable grounding in your outlet wall instead to your monitor.
But if your home doesnt have cable grounding, you can make one manual like image below.
Use cable grounding type and hook one of screw pc case near PSU and pin to wall, so any leak electricity will transfer to wall.
Outlet wall that use for my pc doesnt have cable grounding so affect my lenovo, i use second option and now rarely get black screen.
But again if you not confident with second option, you must consult with expert because electricity is dangerous.
Sorry my english is so bad, hope you understand.