How to investigate how a black screen was stuck?

EDIT: I though I was in the Windows 7 Forum. If a moderator wishes to remove this post that's fine with me: I'll go to the Windows 7 Forum . I just looked up whether or not I could delete my post but wasn't able to. I'd like to as that a moderator does delete it. Thank you.

I This is my first post in the Windows 7 forum and I spend most of my time in the Windows 10 forum.

My brother has a Win7 desktop and yesterday he called and asked me to check out his computer because it wouldn't start up.
So I get there and see that the computer is on but the screen is black. I was hoping it just had to come out of sleep mode but that didn't work. I ended up doing a hard shut down. It started back up with the black screen with the choices to start up normally and other choices: I let it start normally and all went well.

My question is, is there a way to investigate what had happened?
--- Can Event Viewer be helpful?
--- I did some research on how to use Event Viewer but I can't tell where to look.

MeAndMyComputer said:

My question is, is there a way to investigate what had happened?
--- Can Event Viewer be helpful?
--- I did some research on how to use Event Viewer but I can't tell where to look.

I'm not sure if this helps but:

1. once you are in Event Viewer click on (in the left pane) Windows Logs and from the list below System. Now go to the right pane and click on Filter Current Log... and from Event sources list choose Power-Troubleshooter (if it was power-related issue).

2. you may also try to go to Control Panel / Security and Maintenance / under Maintenance you'll find View Reliability History.

Thanks Win10Pro, I'll be following up on your ideas.

MeAndMyComputer said:

Thanks Win10Pro, I'll be following up on your ideas.

No problem, just let us know if this helped so other people with identical problem could benefit.