I had a flickering screen and when I was using the computer it locked up with a black screen.
I looked up info on how to fix the problem of flickering. I tried a couple of the suggestions but they did not help.
Then I tried one that said to "Run MSFCONFIG and select SAFE BOOT, restart,"
After doing that I was stuck on the screen that asks for password. I use a four digit pin but not the pin no longer works.
I shut it off and restarted, but the pin I had used before on startup will not work.