Display Not Showing Bottom 20% of the Screen

[Guest]

Greetings,

I recently removed my HDMI cable of my 2nd screen during sleep mode of my laptop and it resulted in the bottom 20% of my laptop display not showing. The laptop display then returns to normal (shows 100% of the screen) whenever I reattach the HDMI cable for the second display.

As a test, I decided to try LXDE to see if it displayed properly without an HDMI connection and, it did.

How do I go about diagnosing and repairing this? BTW, I'm on 16.04 LTS.

If there's anything else you need that's relevant to fixing this that I didn't provide, please just ask.

Thanks for taking the time to read my post.

[Snowhog]

As a test, I decided to try LXDE to see if it displayed properly without an HDMI connection and, it did.

Was this 'test' conducted in the same way, i.e., with the HDMI cable connected to the 2nd screen, waiting for the laptop to enter sleep mode, and then removing the HDMI cable? And if 'yes', disconnecting the HDMI cable did not result in the bottom 20% of your laptop display not showing?

What make/model of laptop do you have? What GPU does it have?

[Guest]

Yes and the LXDE display function still remained in its entirety (20% display not missing). I triggered sleep by closing the lid and removing the HDMI a few hours later. That's when the display issue happened with Plasma.

I'm using an HP 15-d035dx. It has the integrated Intel APU.

Also, I don't know if it's relevant but, the login screen is completely shown until I log into my account. That's when the bottom 20% just blacks out when using Plasma but not LXDE using the laptop display only.