Why does my screen turn off when I unplug my charger?
When i unplug my charger for my HP Elitebook840, my screen goes almost black so that you cannot see anything at all and you have to plug it back in. How can I fix this?
It may be that the laptop’s battery is not capable of supplying enough power to run the computer as well as the screen and may need to be replaced.
If you have Win 10 installed in the laptop, try creating a Win 10 battery report to check the status of the battery.
What is the exact model number of your laptop, as there are several Elitebook 840 variants?