Desktop not recognizing monitor (possibly not mouse and keyboard) after monitor is powered down

[Tellanus]

I need your help fixing my father's computer. I am currently at my parents' house helping them get through a serious illness and don't have access to my normal resources. I am out of ideas on how to fix their computer and would love some help. Here is the issue:

My parent's computer is an HP H8-1414 running Windows 10 https://support.hp.com/us-en/document/c03517389

The issue is that when the monitor was physically turned off while the computer remained on the monitor failed to be recognized the next morning.

I then attempted a hard power down of the computer and restarted but it did the same thing. I also noticed that after the computer is turned on - all the fans run and all the lights activate - the keyboard does not register the caps lock or num lock lights. The mouse also does not illuminate but his model might just not do that - its an old OEM.

I really don't know where to start. This happens with a spare monitor as well so seems to be something with the desktop and he said it happened once before and then resolved itself somehow. 

Thoughts?

[Echo_Lake]

@Tellanus

Thank you for posting on HP Support Community.

Don't worry as I'll be glad to help, I have a few troubleshooting steps we could try to fix the issue:  

Firstly, perform Windows Update and HP Support Assistant: (do not skip any troubleshooting steps if you feel steps are repeating) 

To check for updates now, select the Start button, and then go to Settings  > Update & security  > Windows Update, and select Check for updates.

Install updates from HP Support Assistant: Go to Download HP Support Assistant to install the tool.

1. To open HP Support Assistant, double-click the HP Support Assistant icon .
2. Click My devices in the top menu, and then click Updates in the  My PC
3. Click Check for updates and messages to scan for new updates.
4. Review the list of updates. Updates with a yellow information icon are recommended. Updates with a blue information icon are optional.
5. Click the update name for a description, version number, and file size.
6. Select the box next to any updates you want to install, and then click Download and install.

Click here: https://support.hp.com/in-en/document/c03383935 to know more about Sleep and Hibernate Issues (Windows 10, 😎

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.